Document

424B3 1 a424b3prospectussupplement.htm 424B3 Document

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-293786

PROSPECTUS SUPPLEMENT

(to Prospectus dated February 26, 2026)

14,768 Shares

Kratos Defense & Security Solutions, Inc.

Common Stock

This prospectus supplement supplements information contained in that certain prospectus dated February 26, 2026 filed as part of that certain registration statement on Form S-3 filed with the U.S. Securities and Exchange Commission (the “SEC”) on February 26, 2026 and relates to the offer and sale from time to time by the selling stockholders named herein of up to 14,768 shares of the common stock, par value $0.001 per share (the “common stock”), of Kratos Defense & Security Solutions, Inc. (the “Company”). We are registering the resale of the shares of common stock covered by this prospectus supplement as required by the terms of the Agreement and Plan of Merger that we entered into with the selling stockholders and the other parties named therein on February 11, 2026 (the “Merger Agreement”).

Our registration of the shares of common stock covered by this prospectus supplement does not mean that the selling stockholders will offer or sell any of the shares. The selling stockholders may offer and sell or otherwise dispose of the shares of common stock described in this prospectus supplement from time to time through public or private transactions at prevailing market prices, at prices related to prevailing market prices or at privately negotiated prices. See “Plan of Distribution” beginning on page S-15 for more information.

We will not receive any of the proceeds from the sale of shares of common stock by the selling stockholders. The selling stockholders will pay all underwriting discounts and selling commissions, if any, in connection with the sale of the shares of common stock. We have agreed to pay certain expenses in connection with this prospectus supplement. As of the date of this prospectus supplement, no underwriter or other person has been engaged to facilitate the sale of shares of common stock in this offering.

You should read this prospectus supplement, any subsequent, applicable prospectus supplement and any related free writing prospectus carefully before you invest.

Our common stock is listed on The Nasdaq Global Select Market under the symbol “KTOS.” On April 16, 2026, the last reported sale price of our common stock on The Nasdaq Global Select Market was $74.41. Investing in our securities involves various risks and uncertainties. You should carefully review the risks and uncertainties described under the heading “Risk Factors” beginning on page S-7 and contained under similar headings in the other documents that we incorporate by reference into this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is April 17, 2026.

TABLE OF CONTENTS

Prospectus Supplement


			Page
ABOUT THIS PROSPECTUS SUPPLEMENT			S-1
TRADEMARKS, SERVICE MARKS AND TRADENAMES			S-2
MARKET AND INDUSTRY DATA			S-3
PROSPECTUS SUPPLEMENT SUMMARY			S-4
RISK FACTORS			S-7
SPECIAL NOTE REGARDING FORWARD-LOOKING INFORMATION			S-9
USE OF PROCEEDS			S-11
DIVIDEND POLICY			S-12
THE SELLING STOCKHOLDERS			S-13
PLAN OF DISTRIBUTION			S-15
MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS			S-17
CERTAIN ERISA CONSIDERATIONS			S-20
VALIDITY OF SECURITIES			S-22
EXPERTS			S-23
WHERE YOU CAN FIND ADDITIONAL INFORMATION			S-24
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE			S-25

Prospectus


			Page
ABOUT THIS PROSPECTUS			1
SUMMARY			3
RISK FACTORS			5
FORWARD-LOOKING STATEMENTS			6
USE OF PROCEEDS			7
SELLING SECURITY HOLDERS			8
PLAN OF DISTRIBUTION			9
DESCRIPTION OF CAPITAL STOCK			11
DESCRIPTION OF DEBT SECURITIES			15
DESCRIPTION OF WARRANTS			22
DESCRIPTION OF RIGHTS			24
DESCRIPTION OF UNITS			25
LEGAL OWNERSHIP OF SECURITIES			26
LEGAL MATTERS			29
EXPERTS			29
WHERE YOU CAN FIND ADDITIONAL INFORMATION			29
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE			30

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ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying prospectus are part of an automatic shelf registration statement that we filed with the Securities and Exchange Commission (“SEC”), as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”), utilizing a “shelf” registration process. This document is in two parts. The first part is this prospectus supplement, including the documents incorporated by reference, which describes the specific terms of this offering. The second part, the accompanying prospectus, including the documents incorporated by reference, provides more general information. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. We urge you to carefully read this prospectus supplement and the accompanying prospectus, and the documents incorporated by reference herein and therein, before buying any of the securities being offered under this prospectus supplement. This prospectus supplement may add to or update information contained in the accompanying prospectus and the documents incorporated by reference therein. To the extent that any statement we make in this prospectus supplement is inconsistent with statements made in the accompanying prospectus or any documents incorporated by reference therein that were filed before the date of this prospectus supplement, the statements made in this prospectus supplement will be deemed to modify or supersede those made in the accompanying prospectus and such documents incorporated by reference therein.

You should rely only on the information contained in this prospectus supplement and the accompanying prospectus, or incorporated by reference herein or therein. We have not authorized anyone to provide you with different information. No underwriter, dealer, salesperson or other person, including us, has authorized anyone to give you any information or to represent anything not contained in this prospectus supplement and the accompanying prospectus. You should not rely on any unauthorized information or representation. We do not take any responsibility for, and cannot provide any assurance as to the reliability of, any information other than the information contained in this prospectus supplement and the accompanying prospectus, or incorporated herein or therein. This prospectus supplement is an offer to sell only the securities offered hereby and only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information in this prospectus supplement and the accompanying prospectus is accurate only as of the date on the front of the applicable document and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the date of delivery of this prospectus supplement or the accompanying prospectus, or any sale of a security. Our business, financial condition, liquidity, results of operations and prospects may have changed since those dates.

Unless otherwise mentioned or unless the context requires otherwise, all references in this prospectus to “the Company,” “we,” “us,” “our” and “Kratos” refer to Kratos Defense & Security Solutions, Inc., a Delaware corporation, and its consolidated subsidiaries.

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TRADEMARKS, SERVICE MARKS AND TRADENAMES

We own or have rights to trademarks, service marks or trade names that we use in connection with the operation of our business. We also own or have the rights to copyrights that protect the content of our products. Solely for convenience, the trademarks, service marks, tradenames and copyrights referred to in this prospectus supplement are listed without the ©, ® and ™ symbols, but we will assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensors to these trademarks, service marks and trade names.

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MARKET AND INDUSTRY DATA

The market data and certain other statistical information used throughout this prospectus is based on independent industry publications, government publications and other published independent sources. Although we believe these third-party sources are reliable as of their respective dates, neither we nor the selling stockholders have independently verified the accuracy or completeness of this information. The industry in which we operate is subject to a high degree of uncertainty and risk due to a variety of factors, including those described in the section entitled “Risk Factors.” These and other factors could cause results to differ materially from those expressed in these publications.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary is not complete and does not contain all of the information that you should consider before investing in the securities offered by this prospectus supplement. You should read this summary together with the entire prospectus supplement and the accompanying prospectus, including our consolidated financial statements, the notes to those consolidated financial statements, our Annual Report on Form 10-K for the fiscal year ended December 29, 2024, (the “Annual Report”), and the other documents that are incorporated by reference in this prospectus supplement and the accompanying prospectus, before making an investment decision. See “Risk Factors” beginning on page S-7 of this prospectus supplement for a discussion of the risks involved in investing in our securities.

Our Business

Kratos is a technology, products, system and software company addressing the defense, national security, and commercial markets. Kratos makes true internally funded research, development, capital and other investments, to rapidly develop, produce and field solutions that address our customers’ mission critical needs and requirements. At Kratos, affordability is a technology, and we seek to utilize proven, leading-edge approaches and technology, not unproven bleeding edge approaches or technology, with Kratos’ approach designed to reduce cost, schedule and risk, enabling us to be first to market with cost effective solutions. We believe that Kratos is known as an innovative disruptive change agent in the industry, a company that is an expert in designing products and systems up front for successful rapid, large quantity, low-cost future manufacturing which is a value-add competitive differentiator for our large traditional prime system integrator partners and also to our government and commercial customers. Kratos intends to pursue program and contract opportunities as the prime or lead contractor when we believe that our probability of win (PWin) is high and any investment required by Kratos is within our capital resource comfort level. We intend to partner and team with a large, traditional system integrator when our assessment of PWin is greater or required investment is beyond Kratos’ comfort level. Kratos’ primary business areas include virtualized ground systems for satellites and space vehicles including software for command & control (C2) and telemetry, tracking and control (TT&C), jet powered unmanned aerial drone systems, hypersonic vehicles and rocket systems, propulsion systems for drones, missiles, loitering munitions, supersonic systems, space craft and launch systems, C5ISR and microwave electronic products for missile, radar, missile defense, space, satellite, counter UAS, directed energy, communication and other systems, and virtual & augmented reality training systems for the warfighter.

Merger Agreement

The following is a summary of the transactions relating to the securities being registered hereunder:

On February 11, 2026, we entered into an Agreement and Plan of Merger (the “Merger Agreement”) pursuant to which we agreed to acquire Nomad Global Communication Solutions, Incorporated, a Montana corporation (“Nomad”), pursuant to a reverse triangular merger whereby Nomad would merge with and into our newly formed merger subsidiary, with Nomad surviving the merger as our wholly owned subsidiary. Nomad is a hardware, products and systems company, focused on the National Security, defense, homeland security and commercial markets. Nomad supports every branch of the armed forces of the United States, including with Nomad’s mobile command, control, communications, satellite communication and counter UAS related systems. The transaction with Nomad was a “negotiated” deal between Kratos and the owners of Nomad. Pursuant to the Merger Agreement, (a) on February 11, 2026, we issued an aggregate of 972,136 shares of our common stock to Seth Alan Schmautz, Will Elias Schmautz, Clayton Charles Binford, and Shane Roger Ackerly (each, a “selling stockholder” and, collectively, the “selling stockholders”), (b) we agreed to issue up to $7 million worth of additional shares of our common stock to the selling stockholders in the future upon release of certain holdback amounts, (c) we agreed to pay up to $6 million in cash to the selling stockholders in the future upon release of a certain holdback amount, and (d) we agreed to issue up to $10 million worth of additional shares of our common stock to the selling stockholders upon achievement of certain milestones set forth in the Merger Agreement. Under the terms of the Merger Agreement, we agreed to register the sale or other disposition of the shares of our common stock issued to the selling stockholders pursuant to the Merger Agreement. Following the closing of the transactions contemplated by the Merger Agreement, Nomad became our wholly owned subsidiary.

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On April 16, 2026, pursuant to the Merger Agreement, we issued an aggregate of 14,768 shares of our common stock to the selling stockholders in connection with a release of a portion of the holdback amounts referred to in clause (b) of the immediately preceding paragraph.

Our Corporate Information

We were initially incorporated in the state of New York in 1994 and began operations in March 1995. We reincorporated in the state of Delaware in 1998. On September 12, 2007, we changed our name from Wireless Facilities, Inc. to Kratos Defense & Security Solutions, Inc. Our principal executive offices are located at 1 Chisholm Trail, Suite 3200, Round Rock, Texas 78681, and our telephone number is (512) 238-9840. We maintain an internet website at www.kratosdefense.com. We have included our website address in this prospectus supplement solely as an inactive textual reference. We do not incorporate the information on, or accessible through, our website into this prospectus supplement, and you should not consider any information on or accessible through our website as part of this prospectus supplement.

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THE OFFERING


Issuer						Kratos Defense & Security Solutions, Inc.

Securities offered:						14,768 shares of our common stock

Common Stock to be outstanding after the offering:						187,438,489 shares of our common stock

Selling Stockholders:						All of the shares of common stock covered by this prospectus supplement are being offered by the selling stockholders identified in the section entitled “The Selling Stockholders” beginning on page S-13 of this prospectus supplement.

Dividend policy:						We currently intend to retain any future earnings to finance the growth and development of the business and, therefore, do not anticipate paying any cash dividends in the foreseeable future. In addition, our ability to pay dividends is restricted by the terms of the agreements governing our credit agreement. Any future determination to pay cash dividends or engage in stock buybacks will be at the discretion of our board of directors and will be dependent upon our future financial condition, results of operations, capital requirements, contractual obligations, general business conditions and other relevant factors as determined by our board of directors.

Nasdaq Global Select Market symbol:						“KTOS”

Risk factors:						An investment in our common stock involves various risks and uncertainties. See “Risk Factors” beginning on page S-7 of this prospectus supplement, on page 4 of the accompanying prospectus and in the documents incorporated by reference into this prospectus supplement for a discussion of factors you should carefully consider before deciding to invest in our common stock.

The number of shares of our common stock to be outstanding immediately after the closing of this offering is based on 187,423,721 shares of common stock outstanding as of April 16, 2026 and excludes, as of that date:

•3,642,008 shares of common stock available for future grant under our 2023 Employee Stock Purchase Plan and our 2023 Equity Incentive Plan; and

•4,322,170 shares of common stock issuable upon the vesting and settlement of restricted stock units.

S-6

RISK FACTORS

An investment in our common stock involves a substantial risk of loss. You should carefully consider the following risk factors and all other information contained herein as well as the information included or incorporated by reference in this prospectus supplement and the accompanying prospectus before you decide to invest in our common stock. The occurrence of any of the following risks could harm our business. In that case, the trading price of our common stock could decline, and you may lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also impair our operations. You should also refer to the other information contained in this prospectus supplement and the accompanying prospectus or incorporated by reference herein or therein, including our financial statements and the notes to those statements, as well as the information contained in our Annual Report which is incorporated by reference herein, and the information set forth under the heading “Special Note Regarding Forward-Looking Statements.”

Risks Related to Investments in Our Securities

Our stock price may be volatile, and your investment in our stock could suffer a decline in value.

The market price of our common stock may fluctuate significantly, and you may not be able to resell your shares at or above the price at which you purchased your shares. Factors which could have a significant impact on the market price of our common stock include, but are not limited to, the following, most of which we cannot control:

•quarterly variations in operating results;

•changes in preference by our customers;

•announcements of new services or products or significant price reductions by us or our competitors or other actions by our competitors;

•the gain or loss of significant customers;

•stock price performance or changes in the market valuations of our competitors;

•changes in analysts’ earnings estimates or publication of research reports about our industry;

•rumors or dissemination of false information;

•default on our indebtedness;

•changes in our senior management or key personnel;

•pricing pressures;

•fluctuations in stock market prices and volumes;

•short selling of our common stock;

•litigation and government inquiries;

•general conditions in the market;

•the extent and duration of any pandemics or other public health risks;

•political and/or military events associated with current worldwide conflicts; and

•events affecting other companies that investors deem comparable to us.

These and other external factors may cause the market price and demand for our common stock to fluctuate substantially, which may limit or prevent investors from readily selling their shares of common stock and may

S-7

otherwise negatively affect the liquidity of our common stock. Volatility in the market price of our common stock could also subject us to securities class action litigation.

Future sales of our common stock could cause the market price for our common stock to decline.

We cannot predict the effect, if any, that market sales of shares of our common stock or the availability of shares of our common stock for sale will have on the market price of our common stock prevailing from time to time. Sales of substantial amounts of shares of our common stock in the public market, or the perception that those sales will occur, could cause the market price of our common stock to decline or be depressed.

The shares of our common stock covered by this prospectus supplement will be freely tradable without restriction or further registration under the Securities Act. However, pursuant to the Merger Agreement, the selling stockholders agreed to limit resales of our common stock issued pursuant to the Merger Agreement on any trading day to no more than 10% of the 30-day average trading volume for our common stock as reported by Bloomberg Financial Markets on such trading day.

In the future, we may issue our securities if we need to raise capital in connection with a capital expenditure, working capital requirement or acquisitions. For example, pursuant to the terms of the Merger Agreement, we agreed to issue up to an additional $7 million worth of shares of our common stock to the selling stockholders upon release of certain holdbacks (a portion of which are covered by this prospectus supplement) and up to an additional $10 million worth of shares of our common stock to the selling stockholders upon achievement of certain milestones set forth in the Merger Agreement. The amount of shares of our common stock issued in connection with a capital expenditure, working capital requirement or acquisitions could constitute a material portion of our then-outstanding shares of common stock. Any perceived excess in the supply of our shares in the market could negatively impact our share price and any issuance of additional securities in connection with investments or acquisitions may result in additional dilution to you.

We do not expect to pay any cash dividends or buyback any Kratos stock for the foreseeable future.

We have not declared any cash dividends since becoming a public company. We currently intend to retain any future earnings to finance the growth and development of the business and, therefore, we do not anticipate that we will pay any cash dividends on shares of our common stock in the foreseeable future. In addition, our ability to pay dividends and buyback Kratos stock is restricted by our credit facility. Any determination to pay dividends or buyback Kratos stock in the future will be at the discretion of our board of directors and will be dependent upon our future financial condition, results of operations and capital requirements, contractual obligations, general business conditions and other relevant factors as determined by our board of directors. Accordingly, if you purchase shares in this offering, realization of a gain on your investment will depend on the appreciation of the price of our common stock, which may never occur. Investors seeking cash dividends in the foreseeable future should not purchase our common stock. See “Dividend Policy.”

If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business, our stock price and any trading volume could decline.

The trading market for our securities depends in part on the research and reports that industry or financial analysts publish about us or our business. We do not influence or control the reporting of these analysts. If one or more of the analysts who do cover us downgrade or provide a negative outlook on our company or our industry, or the stock of any of our competitors, the price of our common stock could decline. If one or more of these analysts ceases coverage of our company, we could lose visibility in the market, which in turn could cause the price of our common stock to decline.

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SPECIAL NOTE REGARDING FORWARD-LOOKING INFORMATION

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein contain forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed in or implied by the forward-looking statements. Forward-looking statements may include, but are not limited to, statements relating to our future financial performance, the growth of the market for our services, expansion plans and opportunities and statements regarding our intended uses of the proceeds of the securities offered hereby. In some cases, you can identify forward-looking statements by terminology such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” or “continue,” the negative of such terms or other comparable terminology.

These forward-looking statements contained in or incorporated by reference into this prospectus supplement reflect our current beliefs, expectations and projections, are based on assumptions, and are subject to known and unknown risks and uncertainties that could cause our actual results or achievements to differ materially from any future results or achievements expressed in or implied by our forward-looking statements, including the factors listed below. Many of these factors are beyond our ability to control or predict. As a result, you should not place undue reliance on forward-looking statements. The most important risks and uncertainties that could cause our actual results or achievements to differ materially from the results or achievements expressed in or implied by our forward-looking statements, include, but are not limited to:

•changes, cutbacks or delays in spending by the U.S. Department of Defense may occur which could cause delays or cancellations of key government contracts;

•delays to or the cancellation of our projects as a result of protest actions submitted by our competitors;

•changes in federal government (or other applicable) procurement laws, regulations, policies and budgets;

•the availability of government funding for the Company’s products and services due to performance, cost growth, or other factors;

•changes in government and customer priorities and requirements;

•risks related to natural disasters or severe weather;

•changes in the scope or timing of our projects;

•the timing, rescheduling or cancellation of significant customer contracts and agreements, or consolidation by or the loss of key customers;

•risks associated with debt leverage;

•failure to successfully achieve our integration, cost reduction or divestiture strategies;

•risks related to security breaches, cybersecurity attacks or other significant disruptions of our information systems;

•competition in the marketplace, which could reduce revenues and profit margins;

•risks of adverse regulatory action or litigation;

•risks that potential future goodwill impairments will adversely affect our operating results;

•risks that anticipated tax benefits will not be realized in accordance with our expectations; and

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•risks that a change in ownership of our stock could cause further limitation to the future utilization of our net operating loss carryforwards.

The forward-looking statements contained in this prospectus supplement reflect our views and assumptions only as of the date of this prospectus supplement or as of the date of the accompanying prospectus or the documents incorporated by reference. You should not place undue reliance on forward-looking statements. Except as required by law, we assume no responsibility for updating any forward-looking statements nor do we intend to do so. Our actual results, performance or achievements could differ materially from the results expressed in, or implied by, these forward-looking statements. The risks included in this section are not exhaustive. There may be other factors that could cause actual results to differ materially from those described in the forward-looking statements, including those described in the sections entitled “Risk Factors” beginning on page S-7, “Risk Factors” appearing in Item 1A of our Annual Report incorporated herein by reference, and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” appearing in Item 7 of our Annual Report incorporated herein by reference.

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USE OF PROCEEDS

We will receive no proceeds from the sale of our common stock by the selling stockholders. The selling stockholders will pay any discounts, selling commissions and stock transfer taxes applicable to its sale of our common stock and any fees and expenses of its counsel and accountants related to the selling stockholders’ sale or distribution of our common stock. We will bear all other costs, fees and expenses incurred in effecting the registration of our common stock covered by this prospectus supplement. These may include, without limitation, all registration, filing and listing fees, printing expenses, blue sky fees and expenses, and any fees and expenses of our counsel and accountants.

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DIVIDEND POLICY

We have not declared any cash dividends since becoming a public company. We currently intend to retain any future earnings to finance the growth and development of our business and, therefore, do not anticipate paying any cash dividends in the foreseeable future. In addition, our ability to pay dividends is restricted by our credit agreement, as discussed in the section entitled “Liquidity and Capital Resources” in Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and Note 5 of the Notes to Consolidated Financial Statements contained in our Annual Report incorporated herein by reference. Any future determination to pay cash dividends will be at the discretion of our board of directors and will be dependent upon our future financial condition, results of operations and capital requirements, general business conditions and other relevant factors as determined by our board of directors.

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THE SELLING STOCKHOLDERS

This prospectus supplement relates to the resale by the selling stockholders named below, from time to time, of up to 14,768 shares of our common stock issued to the selling stockholders as described above under the heading “Prospectus Summary – Merger Agreement.”

We do not know when or in what amounts the selling stockholders may sell or otherwise dispose of the shares covered hereby. The selling stockholders might not sell any or all of the shares covered by this prospectus supplement or may sell or dispose of some or all of the shares other than pursuant to this prospectus supplement. Because the selling stockholders may not sell or otherwise dispose of some or all of the shares covered by this prospectus supplement and because there are currently no agreements, arrangements or understandings with any person to sell or distribute its shares, we cannot estimate the number of shares that will be held by the selling stockholders after completion of the offering. For purposes of the table below, we have assumed that the selling stockholders will have sold all of the shares covered by this prospectus supplement upon completion of the offering.

The selling stockholders acquired the shares of our common stock that we are registering for resale pursuant to this prospectus supplement from us pursuant to the terms of the Merger Agreement. Our issuance of the shares of our common stock to the selling stockholders was exempt from registration under the Securities Act. This prospectus supplement is being filed pursuant to our obligations under the terms of the Merger Agreement.

Under the terms of the Merger Agreement, we are obligated to file a registration statement covering the resale by the selling stockholders of the shares of our common stock that we issued pursuant to the Merger Agreement. We also must use commercially reasonable efforts to prepare and file with the SEC such amendments and supplements to the registration statement as may be necessary to keep the registration statement effective and to comply with the provisions of the Securities Act with respect to the disposition of all of our common stock covered by the registration statement until the first to occur of: (i) the date on which all of our common stock issued pursuant to the Merger Agreement have been sold, and (ii) the date on which our common stock issued pursuant to the Merger Agreement may be sold without restriction pursuant to Rule 144. The Merger Agreement requires that we bear all expenses of registering the shares of our common stock issued pursuant to the Merger Agreement, with the exception of discounts, selling commissions and stock transfer taxes applicable to the selling stockholder’s sale of our common stock, as well as any fees and disbursements of financial advisors for the selling stockholders and similar commissions relating to the selling stockholders’ disposition of the shares of our common stock issued pursuant to the Merger Agreement and expenses of its counsel and accountants.

Unless otherwise indicated in footnotes below, the selling stockholders and their affiliates do not have and, within the past three years has not had, any position, office or other material relationship with us or any of our affiliates other than as a result of (a) the terms of the Merger Agreement, (b) employment of affiliates of the selling stockholders by us or any of our subsidiaries, and (c) the selling stockholders’ beneficial ownership of our common stock. To our knowledge, none of the selling stockholders is a broker-dealer or affiliate of a broker-dealer, nor at the time of the execution of the Merger Agreement and the other agreements contemplated thereby, did any selling stockholder have a direct or indirect agreement or understanding with any person to distribute our shares of common stock. Information about the selling stockholders may change from time to time. Any changed information will be set forth in prospectus supplements, if required by applicable law.

The selling stockholders have represented to us in writing that it acquired the securities for its own account and not with a view to reselling or distributing such securities or any part thereof in violation of the Securities Act. In recognition of the fact that the selling stockholders, even though acquiring the shares for its own account, may wish to be legally permitted to sell the securities when it deems appropriate, we agreed with the selling stockholders to register the resale of the securities.

The table below presents information regarding the selling stockholders and the shares of our common stock that the selling stockholders may sell or otherwise dispose of from time to time under this prospectus supplement. The percentage of beneficial ownership is based upon 187,423,721 shares of our common stock issued and outstanding as of April 15, 2026. Beneficial ownership is determined under Section 13(d) of the Exchange Act and generally includes voting or investment power with respect to securities and includes any securities that grant the

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selling stockholders the right to acquire our common stock within 60 days of the date hereof. Information in the table below is based on information provided by or on behalf of the selling stockholders. Since the date on which the selling stockholders provided us with the information below, the selling stockholders may have sold, transferred or otherwise disposed of some or all of its shares in transactions exempt from the registration requirements of the Securities Act.


	Common Stock Beneficially Owned Prior to Offering	Maximum Number of Shares of Common Stock to be Offered Pursuant to this Prospectus Supplement	Common Stock Owned After Offering(1)
Name of Selling Stockholder	Number	Number	Number	Percent
Seth Alan Schmautz (2)	143,170	3,692	143,170		(3)
Clayton Charles Binford (2)	143,159	3,692	143,159		(3)
Shane Roger Ackerly (2)	161,761	3,692	161,761		(3)
Will Elias Schmautz (2)	170,438	3,692	170,438		(3)

__________________

(1)For purposes of this table, the Company assumes that all of the shares covered by this prospectus supplement will be sold by the selling stockholders. Certain shares of common stock owned after this offering reflected in this table were covered by a prospectus supplement we previously filed with the SEC on February 12, 2026 in connection with a previous issuance of shares of our common stock pursuant to the Merger Agreement on February 11, 2026.

(2)Clayton Charles Binford serves as VP of People Operations – Nomad Global Communication Solutions, Incorporated, our wholly owned subsidiary. Seth Alan Schmautz serves as Sr. Director of Business Integration of Nomad Global Communication Solutions, Incorporated, our wholly owned subsidiary. Shane Roger Ackerly serves as Sr. Director of Manufacturing Engineering of Nomad Global Communication Solutions, Incorporated, our wholly owned subsidiary. Will Elias Schmautz serves as Senior Vice President of Nomad Global Communication Solutions, Incorporated, our wholly owned subsidiary.

(3)Less than 1%.

Each time a selling stockholder sells any shares of common stock offered by this prospectus supplement, he is required to provide you with this prospectus supplement and any subsequent, related prospectus supplement, if any, containing specific information about such selling stockholder and the terms of the shares of our common stock being offered in the manner required by the Securities Act.

We are required, under certain circumstances, to update, supplement or amend this prospectus supplement to reflect material developments in our business, financial position and results of operations and may do so by a prospectus supplement or a future filing with the SEC incorporated by reference in this prospectus.

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PLAN OF DISTRIBUTION

We are registering the shares of our common stock on behalf of the selling stockholders. The selling stockholders will act independently of us in making decisions with respect to the timing, manner and size of each sale. The selling stockholders may, from time to time, sell, transfer or otherwise dispose of the shares of our common stock or interests in the shares of our common stock covered hereby:

•on any stock exchange, market or trading facility on which the shares are traded or in private transactions; or

•through underwriters, broker-dealers or agents, who may receive compensation in the form of discounts, commissions or agent’s commissions from the selling stockholders or the purchasers of our common stock (these discounts, concessions or commissions may be in excess of those customary in the types of transactions involved).

These dispositions may be at fixed prices, at prevailing market prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale, at negotiated prices, or without cash consideration.

The selling stockholders may use any one or more of the following methods when disposing of shares or interests therein:

•sales on any national securities exchange or quotation system on which our common stock may be listed or quoted at the time of the sale;

•sales in the over-the-counter market;

•sales in transactions other than on such exchanges or services or in the over-the-counter market;

•ordinary brokerage transactions and transactions in which the broker-dealer solicits purchasers;

•block trades in which a broker-dealer will attempt to sell the shares as agent, but may position and resell a portion of the block as principal to facilitate the transaction;

•purchases by a broker-dealer as principal and resale by the broker-dealer for its account;

•sales “at the market” to or through a market maker or into an existing trading market, on an exchange or otherwise;

•an exchange distribution in accordance with the rules of the applicable exchange;

•privately negotiated transactions;

•short sales;

•through the writing or settlement of options or other hedging transactions, whether through an options exchange or otherwise;

•broker-dealers may agree with a selling stockholder to sell a specified number of such shares at a stipulated price per share;

•a combination of any such methods of sale or distribution; and

•any other method permitted by applicable law.

The selling stockholders may, from time to time, pledge or grant a security interest in some or all of the shares of our common stock owned by it and, if it defaults in the performance of its secured obligations, the pledgees or secured parties may offer and sell the shares of our common stock, from time to time, under this prospectus supplement, or under an amendment to this prospectus supplement under Rule 424(b)(3) or other applicable

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provision of the Securities Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest of the applicable selling stockholder under this prospectus supplement.

In connection with the sale of our common stock or interests therein, the selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of our common stock in the course of hedging the positions they assume. The selling stockholders may also sell shares of our common stock short and deliver these securities to close out its short positions, or loan or pledge our common stock to broker-dealers or other financial institutions that in turn may sell these securities. The selling stockholders may also enter into option or other transactions with broker-dealers or other financial institutions for the creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of shares offered by this prospectus supplement, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus supplement (as further supplemented or amended to reflect such transaction).

The aggregate proceeds to the selling stockholders from the sale of our common stock offered by it will be the purchase price of our common stock less discounts or commissions, if any. Each selling stockholder reserves the right to accept and, together with its agents from time to time, to reject, in whole or in part, any proposed purchase of our common stock to be made directly or through such agents. We will not receive any of the proceeds from this offering.

The selling stockholders also may resell all or a portion of the shares of our common stock in open market transactions in reliance upon Rule 144 under the Securities Act provided that it meets the criteria and conforms to the requirements of that rule.

The selling stockholders and any underwriters, broker-dealers or agents that participate in the sale of the Common Stock or interests therein may be “underwriters” within the meaning of Section 2(a)(11) of the Securities Act. Any discounts, commissions, concessions or profit they earn on any resale of the shares may be underwriting discounts and commissions under the Securities Act. If any selling stockholder is an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act, he will be subject to the prospectus delivery requirements of the Securities Act.

To the extent required, the shares of our common stock to be sold, the name of the selling stockholders, the purchase prices and public offering prices, the names of any agents, dealers or underwriters and any applicable commissions or discounts with respect to a particular offer will be set forth in a prospectus supplement or, if appropriate, a post-effective amendment to the registration statement that includes this prospectus.

In order to comply with the securities laws of some states, if applicable, our common stock may be sold in these jurisdictions only through registered or licensed brokers or dealers. In addition, in some states our common stock may not be sold unless it has been registered or qualified for sale or an exemption from registration or qualification requirements is available and is complied with.

We have advised the selling stockholders that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of shares in the market and to the activities of the selling stockholders and their affiliates. In addition, to the extent applicable we will make copies of this prospectus (as it may be supplemented or amended from time to time) available to the selling stockholders for the purpose of satisfying the prospectus delivery requirements of the Securities Act. The selling stockholders may indemnify any broker-dealer that participates in transactions involving the sale of the shares against certain liabilities, including liabilities arising under the Securities Act.

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MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS

The following is a summary of the material U.S. federal income tax considerations relevant to the purchase, ownership and disposition of our common stock by a non-U.S. holder (as defined below). This summary deals only with non-U.S. holders that acquire our common stock in this offering and hold the common stock as a capital asset within the meaning of Section 1221 of the Internal Revenue Code of 1986, as amended (the “Code”) (generally, property held for investment).

For purposes of this summary, a “non-U.S. holder” means a beneficial owner of our common stock (other than an entity or arrangement treated as a partnership for U.S. federal income tax purposes) that is not any of the following for U.S. federal income tax purposes: (i) an individual citizen or resident of the U.S.; (ii) a corporation (or other entity treated as a corporation) created or organized in or under the laws of the U.S., any state thereof, or the District of Columbia; (iii) an estate the income of which is subject to U.S. federal income taxation regardless of its source; or (iv) a trust if (1) its administration is subject to the primary supervision of a court within the U.S. and one or more U.S. persons have the authority to control all of its substantial decisions, or (2) it has a valid election in effect under applicable U.S. Treasury regulations to be treated as a U.S. person.

This summary is based upon provisions of the Code and regulations, rulings and judicial decisions as of the date hereof. Those authorities may be changed, perhaps retroactively, or be subject to differing interpretations, so as to result in U.S. federal income tax considerations different from those summarized below. This summary does not represent a detailed description of the U.S. federal income tax considerations to you in light of your particular circumstances. In addition, it does not address the U.S. federal income tax considerations to you if you are subject to special treatment under the U.S. federal income tax laws (including if you are a bank or other financial institution, insurance company, broker or dealer in securities, tax-exempt organization, foreign government or agency, U.S. expatriate, “controlled foreign corporation,” “passive foreign investment company,” a person who is subject to the alternative minimum tax, a person who holds or received our common stock pursuant to the exercise of any employee stock option or otherwise as compensation, or a person who holds our common stock in a straddle or as part of a hedging, conversion or constructive sale transaction). Except where noted, this summary does not address any non-income federal tax consequences, such as estate or gift tax consequences, nor does it address the Medicare tax on net investment income or any state, local, or non-U.S. tax considerations. We cannot assure you that a change in law will not alter significantly the tax considerations that we describe in this summary.

If an entity or arrangement classified as a partnership for U.S. federal income tax purposes holds our common stock, the tax treatment of a partner will generally depend on the status of the partner and the activities of the partnership. If you are a partnership holding our common stock, or a partner in such a partnership, you should consult your tax advisors.

If you are considering the purchase of our common stock, you should consult your own tax advisors concerning the particular U.S. federal tax consequences to you of the purchase, ownership and disposition of our common stock, as well as the consequences to you arising under the laws of any other taxing jurisdiction, including any state, local or foreign tax consequences.

Distributions

We have not declared any cash dividends since becoming a public company and do not anticipate paying any cash dividends on our common stock in the foreseeable future. If we were to pay cash dividends in the future on our common stock, they would be subject to U.S. federal income tax in the manner described below.

Distributions on our common stock generally will constitute dividends for U.S. federal income tax purposes to the extent paid out of our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. Distributions in excess of current and accumulated earnings and profits will be applied against and reduce a non-U.S. holder’s tax basis in our common stock, to the extent thereof, and any excess will be treated as capital gain realized on the sale or other disposition of the common stock and subject to tax in the manner described below under “-Gain on Disposition of Common Stock.”

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Distributions paid to a non-U.S. holder of our common stock that constitute dividends under the rules described above generally will be subject to withholding of U.S. federal income tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. However, dividends that are effectively connected with the conduct of a trade or business by a non-U.S. holder within the U.S. and, where an income tax treaty applies, are attributable to a U.S. permanent establishment of the non-U.S. holder, are not subject to this withholding tax, but instead are subject to U.S. federal income tax on a net income basis at applicable individual or corporate rates. Certain certification and disclosure requirements must be complied with in order for effectively connected dividends to be exempt from this withholding tax. Any such effectively connected dividends received by a foreign corporation may be subject to an additional “branch profits tax” at a 30% rate or such lower rate as may be specified by an applicable income tax treaty.

A non-U.S. holder of our common stock who is entitled to and wishes to claim the benefits of an applicable treaty rate (and avoid backup withholding as discussed below) with respect to dividends received on our common stock, generally will be required (i) to complete Internal Revenue Service (“IRS”) Form W-8BEN or W-8BEN-E (or an acceptable substitute form) and make certain certifications, under penalty of perjury, to establish its status as a non-U.S. person and its entitlement to treaty benefits or (ii) if the common stock is held through certain foreign intermediaries, to satisfy the relevant certification requirements of applicable U.S. Treasury regulations. Special certification and other requirements apply to certain non-U.S. holders that are entities rather than individuals.

A non-U.S. holder of our common stock eligible for a reduced rate of U.S. federal withholding tax pursuant to an income tax treaty may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS.

See the discussions below regarding backup withholding and the Foreign Account Tax Compliance Act, or “FATCA,” for additional withholding rules that may apply to distributions.

Gain on Disposition of Common Stock

Subject to the discussions below regarding backup withholding and FATCA, a non-U.S. holder generally will not be subject to U.S. federal income tax with respect to gain recognized on a sale or other disposition of our common stock unless (i) the gain is effectively connected with a trade or business of the non-U.S. holder within the U.S. and, where an income tax treaty applies, is attributable to a U.S. permanent establishment of the non-U.S. holder, (ii) in the case of a non-U.S. holder who is an individual, such holder is present in the U.S. for 183 or more days in the taxable year of the sale or other disposition and certain other conditions are met, or (iii) subject to certain exceptions, we are or have been a “U.S. real property holding corporation” for U.S. federal income tax purposes and certain other conditions are met.

In the case of a non-U.S. holder described in subsection (i) above, any net gain derived from the disposition generally will be subject to U.S. federal income tax under graduated U.S. federal income tax rates in generally the same manner as if the non-U.S. holder were a United States person as defined under the Code, unless an applicable income tax treaty provides otherwise. Additionally, a non-U.S. holder that is a corporation may be subject to a branch profits tax equal to 30% of its effectively connected earnings and profits attributable to such gain (or, if an income tax treaty applies, at such lower rate as may be specified by the treaty on its gains attributable to its U.S. permanent establishment), subject to adjustments. Except as otherwise provided by an applicable income tax treaty, an individual non-U.S. holder described in subsection (ii) above will be subject to a 30% tax on any gain derived from the disposition, which may be offset by certain U.S. source capital losses. With respect to subsection (iii) above, we believe we have not been and are not currently, and do not anticipate becoming, a “U.S. real property holding corporation” for U.S. federal income tax purposes.

Information Reporting and Backup Withholding

Payors must report annually to the IRS and to each non-U.S. holder the amount of distributions paid to such holder and the tax withheld (if any) with respect to such distributions, regardless of whether withholding was required. Copies of the information returns reporting such distributions and any withholding may also be made available to the tax authorities in the country in which the non-U.S. holder resides under the provisions of an

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applicable income tax treaty. In addition, distributions paid to a non-U.S. holder may be subject to backup withholding unless applicable certification requirements are met.

Payment of the proceeds of a sale of our common stock within the U.S. or conducted through certain U.S. related financial intermediaries is subject to information reporting and, depending upon the circumstances, backup withholding unless the non-U.S. holder certifies under penalties of perjury that it is not a U.S. person (and the payor does not have actual knowledge or reason to know that the holder is a U.S. person) or the holder otherwise establishes an exemption.

Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a non-U.S. holder’s U.S. federal income tax liability provided the required information is timely furnished to the IRS.

Foreign Account Tax Compliance Act

Legislation commonly referred to as FATCA generally imposes a 30% U.S. federal withholding tax on certain types of payments made to (i) a “foreign financial institution” (as specifically defined in the legislation), whether such foreign financial institution is the beneficial owner or an intermediary, unless such foreign financial institution agrees to verify, report and disclose its U.S. “account” holders (as specifically defined in the legislation) and meets certain other specified requirements, or (ii) a non-financial foreign entity, whether such non-financial foreign entity is the beneficial owner or an intermediary, unless such entity provides a certification that the beneficial owner of the payment does not have any substantial U.S. owners or provides the name, address and taxpayer identification number of each such substantial U.S. owner and certain other specified requirements are met. An intergovernmental agreement between the United States and an applicable foreign country may modify the FATCA requirements. In addition, in certain cases, the relevant foreign financial institution or non-financial foreign entity may qualify for an exemption from, or be deemed to be in compliance with, these rules. Under the applicable U.S. Treasury regulations and administrative guidance, withholding under FATCA generally applies to payments of dividends on our common stock. While withholding under FATCA would have applied also to payments of gross proceeds from the sale or other disposition of our common stock on or after January 1, 2019, proposed Treasury regulations eliminate FATCA withholding on payments of gross proceeds entirely. Taxpayers generally may rely on these proposed Treasury regulations until final Treasury regulations are issued.

Investors are urged to consult with their own tax advisors regarding the possible application of these rules to their investment in our common stock.

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CERTAIN ERISA CONSIDERATIONS

The following is a summary of certain considerations associated with the purchase of our common stock, or any interest therein by employee benefit plans that are subject to Title I of the U.S. Employee Retirement Income Security Act of 1974, as amended (“ERISA”), plans, individual retirement accounts and other arrangements that are subject to Section 4975 of the Code or provisions under any U.S. or non-U.S. federal, state, local or other laws or regulations that are similar to such provisions of ERISA or the Code (collectively, “Similar Laws”), and entities whose underlying assets are considered to include “plan assets” of any such plan, account or arrangement (each, a “Plan”).

General Fiduciary Matters

ERISA and the Code impose certain duties on persons who are fiduciaries of a Plan subject to Title I of ERISA or Section 4975 of the Code (a “Covered Plan”) and prohibit certain transactions involving the assets of a Covered Plan and its fiduciaries or other interested parties. Under ERISA and the Code, any person who exercises any discretionary authority or control over the administration of a Covered Plan or the management or disposition of the assets of a Covered Plan, or who renders investment advice for a fee or other compensation to a Covered Plan, is generally considered to be a fiduciary of the Covered Plan.

In considering an investment in our common stock, or any interest therein, using a portion of the assets of any Plan, a fiduciary should determine whether the investment is in accordance with the documents and instruments governing the Plan and the applicable provisions of ERISA, the Code or any Similar Law relating to a fiduciary’s duties to the Plan including, without limitation, the prudence, diversification, delegation of control, conflicts of interest and prohibited transaction provisions of ERISA, the Code and any other applicable Similar Laws. A fiduciary of a Plan should also consider the Plan’s particular circumstances and all of the facts and circumstances of the investment, including, but not limited to, the matters discussed above under “Risk Factors,” in determining whether an investment in our common stock, or any interest therein, satisfies these requirements.

Plan fiduciaries should consider the fact that none of the issuer or the issuer’s affiliates (the “Transaction Parties”) is acting, or will act, as a fiduciary to any Plan with respect to the decision to purchase our common stock, or any interest therein, in connection with the initial offer and sale pursuant to this prospectus supplement. The Transaction Parties are not undertaking to provide impartial investment advice or advice based on any particular investment need, or to give advice in a fiduciary capacity, with respect to such decision to purchase our common stock, or any interest therein.

Prohibited Transaction Issues

Section 406 of ERISA and Section 4975 of the Code prohibit Covered Plans from engaging in specified transactions involving plan assets with persons or entities who are “parties in interest,” within the meaning of ERISA, or “disqualified persons,” within the meaning of Section 4975 of the Code, unless an exemption is available. A party in interest or disqualified person who engaged in a non-exempt prohibited transaction may be subject to excise taxes and other penalties and liabilities under ERISA and the Code. In addition, the fiduciary of the Covered Plan that engages in such a non-exempt prohibited transaction may be subject to penalties and liabilities under ERISA and the Code. The acquisition and/or holding of our common stock, or any interest therein, by a Covered Plan with respect to which is the Transactions Parties are considered a party in interest or a disqualified person may constitute or result in a direct or indirect prohibited transaction under Section 406 of ERISA and/or Section 4975 of the Code, unless the investment is acquired and is held in accordance with an applicable statutory, class or individual prohibited transaction exemption. In this regard, the U.S. Department of Labor has issued prohibited transaction class exemptions, or “PTCEs,” that may apply to the acquisition and holding of our common stock, or any interest therein. These class exemptions include, without limitation, PTCE 84-14 respecting transactions determined by independent qualified professional asset managers, PTCE 90-1 respecting insurance company pooled separate accounts, PTCE 91-38 respecting bank collective investment funds, PTCE 95-60 respecting life insurance company general accounts and PTCE 96-23 respecting transactions determined by in-house asset managers, although there can be no assurance that all of the conditions of any such exemptions will be satisfied.

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Because of the foregoing, our common stock, or any interest therein, should not be purchased or held by any person investing “plan assets” of any Plan, unless such purchase and holding will not constitute a non-exempt prohibited transaction under ERISA and the Code or similar violation of any applicable Similar Laws.

Representation

Accordingly, by acceptance of our common stock, or any interest therein, each purchaser and subsequent transferee of our common stock, or any interest therein, will be deemed to have represented and warranted that either (i) no portion of the assets used by such purchaser or transferee to acquire and hold our common stock, or any interest therein, constitutes assets of any Plan or (ii) the purchase and holding of our common stock, or any interest therein, by such purchaser or transferee will not constitute a non-exempt prohibited transaction under Section 406 of ERISA or Section 4975 of the Code or similar violation under any applicable Similar Laws.

The foregoing discussion is general in nature and is not intended to be all inclusive. Due to the complexity of these rules and the penalties that may be imposed upon persons involved in non-exempt prohibited transactions, it is particularly important that fiduciaries, or other persons considering purchasing our common stock, or any interest therein, on behalf of, or with the assets of, any Plan, consult with their counsel regarding the potential applicability of ERISA, Section 4975 of the Code and any Similar Laws to such investment and whether an exemption would be applicable to the purchase and holding of our common stock, or any interest therein.

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VALIDITY OF SECURITIES

The validity of the common stock being offered by this prospectus supplement will be passed upon for us by our counsel, Sheppard, Mullin, Richter & Hampton LLP, Menlo Park, California.

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EXPERTS

The financial statements of the Company as of December 28, 2025, and December 29, 2024, and for each of the three years in the period ended December 28, 2025, incorporated by reference in this prospectus supplement, and the effectiveness of the Company’s internal control over financial reporting, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report. Such financial statements are incorporated by reference in reliance upon the report of such firm, given their authority as experts in accounting and auditing.

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WHERE YOU CAN FIND ADDITIONAL INFORMATION

We file annual, quarterly and special reports, proxy statements and other information with the SEC. The SEC maintains an Internet website at http://www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC, including Kratos. You may also access our reports and proxy statements free of charge at our Internet website, http://www.kratosdefense.com. The information contained in, or that can be accessed through, our website is not part of this prospectus supplement. The prospectus included in this filing is part of a registration statement filed by us with the SEC. The full registration statement can be obtained from the SEC, as indicated above, or from us.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference the information we file with it, which means that we can disclose important information to you by referring you to another document that we have filed separately with the SEC. The information incorporated by reference is considered to be a part of this prospectus supplement and the accompanying prospectus. We hereby incorporate by reference the following information or documents into this prospectus supplement.

•our Annual Report on Form 10-K for the fiscal year ended December 28, 2025 filed with the SEC on February 23, 2026;

•the portions of our Definitive Proxy Statement filed with the SEC on April 2, 2026, incorporated by reference into the Annual Report on Form 10-K for the fiscal year ended December 28, 2025;

•our Current Reports on Form 8-K filed with the SEC on March 2, 2026, March 6, 2026, and March 25, 2026; and

•the description of our common stock contained in our Registration Statement on Form 8-A (File No. 000-27231), filed under Section 12(g) of the Exchange Act on September 3, 1999, including any subsequent amendment or report filed for the purpose of amending such description, including Exhibit 4.4 to the Annual Report on Form 10-K for the fiscal year ended December 29, 2019 (filed with the SEC on February 24, 2020).

Any information in any of the foregoing documents will automatically be deemed to be modified or superseded to the extent that information in this prospectus supplement or the accompanying prospectus or in a later filed document that is incorporated or deemed to be incorporated herein by reference modifies or replaces such information. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

We also incorporate by reference any future filings (other than information in current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, until we sell all of the securities offered by this prospectus supplement. Information in such future filings updates and supplements the information provided in this prospectus supplement. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

Upon written or oral request, we will provide to you, without charge, a copy of any or all of the documents that are incorporated by reference into this prospectus supplement and the accompanying prospectus but not delivered with the prospectus, including exhibits which are specifically incorporated by reference into such documents. Requests should be directed to: Kratos Defense & Security Solutions, Inc., Attention: Investor Relations, 1 Chisholm Trail, Suite 300, Round Rock, TX 78681, telephone (512) 238-9840.

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PROSPECTUS

Kratos Defense & Security Solutions, Inc.

Common Stock

Preferred Stock

Debt Securities

Warrants

Rights

Units

We may from time to time offer to sell any combination of the securities described in this prospectus, either individually or in units, in one or more offerings. In addition, certain selling security holders to be identified in supplements to this prospectus may offer and sell these securities from time to time.

This prospectus provides a general description of the securities we may offer. Each time we sell securities, we will provide specific terms of the securities offered in a supplement to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as any documents incorporated by reference herein or therein before you invest in any securities. This prospectus may not be used to consummate a sale of securities unless accompanied by the applicable prospectus supplement.

Our common stock is listed on The Nasdaq Global Select Market under the symbol “KTOS.” The applicable prospectus supplement will contain information, where applicable, as to any other listing on The Nasdaq Global Select Market or any securities market or other exchange of the securities, if any, covered by the applicable prospectus supplement.

Investing in our securities involves risks. See “Risk Factors” beginning on page 5.

The securities may be offered directly by us or by any selling security holder from time to time, through agents designated by us or to or through underwriters, brokers or dealers. We will provide specific information about any selling security holders in one or more supplements to this prospectus. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus. If any underwriters are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of such underwriters and any applicable commissions or discounts will be set forth in a prospectus supplement or a related free writing prospectus. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement or a related free writing prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is February 26, 2026

TABLE OF CONTENTS


			Page
ABOUT THIS PROSPECTUS			1
SUMMARY			3
RISK FACTORS			5
FORWARD-LOOKING STATEMENTS			6
USE OF PROCEEDS			7
SELLING SECURITY HOLDERS			8
PLAN OF DISTRIBUTION			9
DESCRIPTION OF CAPITAL STOCK			11
DESCRIPTION OF DEBT SECURITIES			15
DESCRIPTION OF WARRANTS			22
DESCRIPTION OF RIGHTS			24
DESCRIPTION OF UNITS			25
LEGAL OWNERSHIP OF SECURITIES			26
LEGAL MATTERS			29
EXPERTS			29
WHERE YOU CAN FIND ADDITIONAL INFORMATION			29
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE			30

ABOUT THIS PROSPECTUS

This prospectus is a part of an automatic shelf registration statement that we filed with the Securities and Exchange Commission (the “SEC”), as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”), utilizing a “shelf” registration process. Under this shelf registration process, we may sell any combination of the securities described in this prospectus in one or more offerings. In addition, selling security holders to be named in a prospectus supplement may sell certain of our securities from time to time. This prospectus provides you with a general description of the securities we may offer. Each time we or any selling security holder offers to sell securities under this shelf registration statement, we or the selling security holder will provide a prospectus supplement that will contain specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus or in any documents that we have incorporated by reference into this prospectus. To the extent that any statement that we make in a prospectus supplement is inconsistent with statements made in this prospectus, the statement made in this prospectus will be deemed modified or superseded by those made in the prospectus supplement. You should read this prospectus, any applicable prospectus supplement and any related free writing prospectus, together with the information incorporated herein by reference as described under the heading “Where You Can Find Additional Information” and “Incorporation of Certain Information by Reference.”

You should rely only on the information that we have provided or incorporated by reference in this prospectus, any applicable prospectus supplement and any related free writing prospectus that we may authorize to be provided to you. You should assume that the information in this prospectus is accurate only as of the date of this prospectus, that any information in any accompanying prospectus supplement is accurate only as of the date of such accompanying prospectus supplement,.and that any information included in another document incorporated by reference herein is accurate only as of the date of such document. We have not authorized any broker, dealer, salesperson or other person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus, any applicable prospectus supplement or any related free writing prospectus that we may authorize to be provided to you. You must not rely upon any information or representation not contained or incorporated by reference in this prospectus, the accompanying prospectus supplement or related free writing prospectus. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you.

This prospectus, any accompanying prospectus supplement, and any related free writing prospectus do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor do this prospectus, any accompanying prospectus supplement, or any related free writing prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference therein is correct on any date subsequent to the date set forth on the front of the document incorporated by reference, even though this prospectus, any applicable prospectus supplement or any related free writing prospectus is delivered or the applicable securities are sold on a later date.

This prospectus, any accompanying prospectus supplement, and any related free writing prospectus may contain estimates and other information concerning our target markets that are based on industry publications, surveys and forecasts. This information involves a number of assumptions and limitations and you are cautioned not to give undue weight to this information. Please read the section of this prospectus entitled “Cautionary Statement Regarding Forward-Looking Statements.” The industry in which we operate and our business are subject to a high degree of uncertainty and risk due to a variety of factors, including those described under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and in our most recent Annual Report on Form 10-K and any subsequently filed Quarterly Reports on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC. These and other factors could cause actual results to differ materially from those expressed in such publications, surveys and forecasts.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the heading “Where You Can Find Additional Information.”

SUMMARY

This summary highlights selected information from this prospectus and the documents incorporated herein by reference and does not contain all of the information that you need to consider in making your investment decision. You should carefully read this entire prospectus, including the risks of investing in our securities discussed under “Risk Factors” beginning on page 5 of this prospectus, the information incorporated herein by reference, including the information in such documents under the heading “Risk Factors” and our financial statements, and the exhibits to the registration statement of which this prospectus is a part. All references in this prospectus to “we,” “us,” “our,” “Kratos,” the “Company” and similar designations refer to Kratos Defense & Security Solutions, Inc. and its consolidated subsidiaries, unless otherwise indicated or as the context otherwise requires.

Our Business

Kratos is a technology, hardware, products, system and software company addressing the defense, national security, and commercial markets. Kratos makes true internally funded research, development, capital and other investments, to rapidly develop, produce and field relevant solutions that address our customers’ mission critical needs and requirements. At Kratos, affordability is a technology, and we seek to utilize proven, leading-edge approaches and technology, not unproven bleeding edge approaches or technology, with Kratos’ approach designed to reduce cost, schedule and risk, enabling us to be first to market with cost effective solutions. We believe that Kratos is known as the innovative disruptive change agent in the industry, a company that is an expert in designing products and systems up front for successful rapid, large quantity, low-cost future manufacturing, which is a value-add competitive differentiator for our large traditional prime system integrator partners and also to our government and commercial customers. Kratos intends to pursue program and contract opportunities as the prime or lead contractor when we believe our probability of win is high and any investment required by Kratos is within our capital resource comfort level. We intend to partner and team with a large, traditional system integrator when our assessment of probability of win is greater or required investment is beyond Kratos’ comfort level. Kratos’ primary business areas include, virtualized ground systems for satellites and space vehicles including software for command & control (C2) and telemetry, tracking and control (TT&C), jet powered unmanned aerial drone systems, hypersonic vehicles and rocket systems, propulsion systems for drones, missiles, loitering munitions, supersonic systems, space craft and launch systems, command, control, communication, computing, combat, intelligence surveillance and reconnaissance (C5ISR) and microwave electronic products for missile, radar, air defense, missile defense, space, satellite, counter unmanned aircraft systems (CUAS), directed energy, communication and other systems, and virtual & augmented reality training systems for the warfighter.

We believe that there is a generational recapitalization of weapon systems and related defense industrial bases occurring globally, including with the United States and its allies, to address individual and potential collective peer and near peer threats, including Russia, China, North Korea and Iran. The Company currently has record levels of backlog and opportunity pipeline. The Company is currently making significant capital, property, plant, equipment and other internally funded investments to address its backlog, current opportunity pipeline, and expected and potential future program and contract awards, including from or with the Department of War, traditional legacy prime systems integrators and partners. These investments include unmanned jet powered aircraft such as Kratos Valkyrie ahead of potential contract award; a hypersonic system fabrication and integration facility including for Kratos Zeus solid rocket missiles (SRMs) and Erinyes hypersonic flight systems in Indiana; the procurement of long lead items for 60 Oriole and 60 Zeus SRM’s for ballistic missile defense related, hypersonic or other expected customer missions; relocation and expansion of our small turbojet engine production capacity in Michigan; establishment of a planned small turbofan jet engine production facility in Oklahoma; expansion of our existing microwave electronics manufacturing facility in Israel, establishment of an additional microwave electronics facility in Israel, including a space qualified facility; expansion of our machining, milling, casting, 3D printing and additive manufacturing capable facility in the United States to support our jet engine and other hardware product and system manufacturing requirements; establishment of a new facility related to the Sentinel intercontinental ballistic missile (ICBM) program; expansion of our unmanned jet drone manufacturing capability; and expansion of existing and construction of additional classified facilities for certain programs and contracts. Investments related to the Company’s Prometheus venture with Rafael and the new turbofan production facility in Oklahoma related to our arrangement with GE Aerospace are expected to begin to ramp up during 2026.

Our Corporate Information

We were initially incorporated in the state of New York in 1994, commenced operations in 1995 and were reincorporated in Delaware in 1998. On September 12, 2007, we changed our name from Wireless Facilities, Inc. to Kratos Defense & Security Solutions, Inc. Our executive offices are located at 1 Chisholm Trail, Suite 300, Round Rock, TX 78681, and our telephone number is (512) 238-9840 . We maintain an Internet website at www.kratosdefense.com. We have included our website address in this prospectus solely as an inactive textual reference. We do not incorporate the information on, or accessible through, our website into this prospectus, and you should not consider any information on or accessible through our website as part of this prospectus. Our common stock trades on The Nasdaq Global Select Market under the trading symbol “KTOS”.

Securities We May Offer

We may offer shares of our common stock and preferred stock, various series of debt securities and warrants or rights to purchase any of such securities, either individually or in units, from time to time under this prospectus, together with any applicable prospectus supplement and related free writing prospectus, at prices and on terms to be determined by market conditions at the time of offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

•designation or classification;

•aggregate principal amount or aggregate offering price;

•maturity, if applicable;

•original issue discount, if any;

•rates and times of payment of interest or dividends, if any;

•redemption, conversion, exchange or sinking fund terms, if any;

•conversion prices, if any;

•ranking;

•restrictive covenants, if any;

•voting or other rights, if any; and

•important U.S. federal income tax considerations.

A prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus or in documents we have incorporated by reference. However, no prospectus supplement or free writing prospectus will offer a security that is not registered and described in this prospectus at the time of the effectiveness of the registration statement of which this prospectus is a part.

THIS PROSPECTUS MAY NOT BE USED TO CONSUMMATE A SALE OF SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

•the names of those agents, underwriters, brokers or dealers;

•applicable fees, discounts and commissions to be paid to them;

•details regarding options to purchase additional securities, if any; and

•the net proceeds to us.

RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should carefully consider the risks and uncertainties described under the section captioned “Risk Factors” contained in our most recent Annual Report on Form 10-K, our most recent Quarterly Report on Form 10-Q and other filings we make with the SEC from time to time, which are incorporated by reference herein in their entirety, together with the other information in this prospectus, the accompanying prospectus supplement, any free writing prospectus, and in the documents incorporated by reference in this prospectus. The risks described in our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and the other filings we make with the SEC incorporated by reference herein are not the only ones facing the Company. Additional risks and uncertainties may also impair our business operations. If any of the risks described in this prospectus, any accompanying prospectus supplement, any related free writing prospectus, our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and the other filings incorporated by reference herein occurs, our business, financial condition, results of operations and future growth prospects could be harmed. In these circumstances, the market price of our common stock or other securities could decline, you may not be able to sell such securities at a favorable price and you may lose all or part of your investment.

FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated herein by reference contain forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). These statements are based on our management’s current beliefs, expectations and assumptions about future events, conditions and results and on information currently available to us. Discussions containing these forward-looking statements may be found, among other places, in the Sections entitled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” incorporated by reference from our most recent Annual Report on Form 10-K and in our Quarterly Reports on Form 10-Q, as well as any amendments thereto, filed with the SEC.

All statements, other than statements of historical fact, included or incorporated herein regarding our strategy, future operations, financial position, future revenues, projected costs, plans, prospects and objectives are forward-looking statements. In some cases, you can identify forward-looking statements by terminology such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” or “continue,” the negative of such terms or other comparable terminology. These forward-looking statements reflect our current beliefs, expectations and projections, are based on assumptions, and are subject to known and unknown risks and uncertainties that could cause our actual results or achievements to differ materially from any future results or achievements expressed in or implied by our forward-looking statements. Many of these factors are beyond our ability to control or predict. As a result, you should not place undue reliance on forward-looking statements. Important risks and uncertainties that could cause our actual results or achievements to differ materially from the results or achievements reflected in our forward-looking statements include, but are not limited to: changes, cutbacks or delays in spending by the U.S. Department of War may occur which could cause delays or cancellations of key government contracts; delays to or the cancellation of our projects as a result of protest actions submitted by our competitors; changes in federal government (or other applicable) procurement laws, regulations, policies and budgets; the availability of government funding for the Company’s products and services due to performance, cost growth, or other factors; changes in government and customer priorities and requirements; the potential of the current economic environment to adversely impact our business; currently unforeseen risks associated with any public health crisis; risks related to natural disasters or severe weather; changes in the scope or timing of our projects; the timing, rescheduling or cancellation of significant customer contracts and agreements, or consolidation by or the loss of key customers; risks of adverse regulatory action or litigation; risks related to our international operations; risks associated with debt leverage; failure to successfully achieve our integration, cost reduction or divestiture strategies; risks related to security breaches, cybersecurity attacks or other significant disruptions of our information systems; and competition in the marketplace, which could reduce revenues and profit margins.

Such statements are based on currently available operating, financial and competitive information and are subject to various risks, uncertainties and assumptions that could cause actual results to differ materially from those anticipated or implied in our forward-looking statements due to a number of factors including, but not limited to, those set forth above or included or incorporated herein, those set forth under the section entitled “Risk Factors” in our most recent Annual Report on Form 10-K and in our Quarterly Reports on Form 10-Q, as well as any amendments thereto filed with the SEC. Given these risks, uncertainties and other factors, many of which are beyond our control, you should not place undue reliance on these forward-looking statements.

Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to revise any forward-looking statements to reflect events or developments occurring after the date of this prospectus, even if new information becomes available in the future.

USE OF PROCEEDS

Except as described in any applicable prospectus supplement and in any free writing prospectuses in connection with a specific offering, we currently intend to use the net proceeds from the sale of the securities offered hereby for general corporate purposes, including, among other things, working capital requirements and potential repayment of indebtedness that may be outstanding at the time of any offering under this prospectus. We may also use a portion of the net proceeds from the sale of the securities offered hereby to acquire or invest in businesses, services and technologies that are complementary to our own, although we have no present commitments or agreements to do so. Accordingly, we will retain broad discretion over the use of such proceeds. Pending these uses, we intend to invest the net proceeds in investment-grade, interest-bearing securities. We will not receive any of the proceeds from sales of securities by selling security holders.

SELLING SECURITY HOLDERS

If the registration statement of which this prospectus forms a part is used by selling security holders for the resale of any securities registered thereunder pursuant to a registration rights agreement to be entered into by us with such selling security holders or otherwise, information about such selling security holders, their beneficial ownership of our securities and their relationship with us will be set forth in a prospectus supplement, any free writing prospectus or in other filings we make with the SEC under the Exchange Act that are incorporated by reference into the registration statement.

PLAN OF DISTRIBUTION

We, or the applicable selling security holders, may sell the securities being offered hereby in one or more of the following ways from time to time:

•through agents to the public or to investors;

•to underwriters, brokers or dealers for resale to the public or to investors;

•in “at the market offerings” within the meaning of Rule 415(a)(4) under the Securities Act, to or through a market maker or into an existing trading market, on an exchange or otherwise;

•directly to investors;

•through a combination of any of these methods of sale; or

•through any other methods described in a prospectus supplement.

Each time we offer and sell securities, we will provide a prospectus supplement or supplements (and any related free writing prospectus that we may authorize to be provided to you) that will describe the terms of the offering of the securities, including, to the extent applicable:

•the name or names of any agents or underwriters, brokers or dealers and the amount of shares underwritten or purchased by each of them;

•the purchase price of the securities being offered and the proceeds we will receive from the sale;

•any over-allotment options under which underwriters may purchase additional securities from us;

•any agency fees or underwriting discounts and other items constituting agents’ or underwriters’ compensation;

•any initial public offering price;

•any discounts or concessions allowed or reallowed or paid to brokers or dealers; and

•any securities exchanges or markets on which such securities may be listed.

We may designate agents who agree to use their reasonable efforts to solicit purchases of our securities for the period of their appointment or to sell our securities on a continuing basis. We will name any agent involved in the offering and sale of securities and we will describe any commissions we will pay to the agent in the applicable prospectus supplement.

If we use underwriters for a sale of securities, the underwriters will acquire the securities for their own account. The underwriters may resell the securities in one or more transactions, including negotiated transactions, at a fixed public offering price, at varying prices determined at the time of sale, at prices related to prevailing market prices or at negotiated prices. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement, other than securities covered by any over-allotment or other option. We may change from time to time any initial public offering price and any discounts or concessions the underwriters allow or reallow or pay to brokers or dealers. We may use underwriters with whom we have a material relationship. We will describe the nature of any such relationship in any prospectus supplement naming any such underwriter. Only underwriters we name in the applicable prospectus supplement are underwriters of the securities offered by such prospectus supplement.

We may also sell securities directly to one or more purchasers without using underwriters or agents. Underwriters, brokers, dealers and agents that participate in the distribution of the securities may be underwriters as defined in the Securities Act, and any discounts or commissions they receive from us and any profit on their resale of the securities may be treated as underwriting discounts and commissions under the Securities Act. We will identify in the applicable prospectus supplement any underwriters, brokers, dealers or agents and will describe their compensation. We may have agreements with the underwriters, brokers, dealers and agents to indemnify them against specified civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which they may be required to make in respect thereof. Underwriters, brokers, dealers and agents may engage in transactions with or perform services for us in the ordinary course of their businesses.

We and/or the selling security holders, if applicable, may authorize underwriters, brokers, dealers or agents to solicit offers by certain purchasers to purchase the securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. The contracts will be subject only to those conditions set forth in the applicable prospectus supplement, and the applicable prospectus supplement will set forth any commissions we pay for solicitation of these contracts.

Unless otherwise specified in the applicable prospectus supplement, each class or series of securities will be a new issue with no established trading market, other than our common stock, which is listed on The Nasdaq Global Select Market. We may elect to list any other class or series of securities on any exchange or market, but we are not obligated to do so. It is possible that one or more underwriters may make a market in a class or series of securities, but the underwriters will not be obligated to do so and may discontinue any market making at any time without notice. We cannot give any assurance as to the liquidity of the exchanges or markets for any of the securities.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Syndicate-covering or other short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of these activities at any time.

Any underwriters who are qualified market makers on The Nasdaq Global Select Market may engage in passive market making transactions in the securities on The Nasdaq Global Select Market in accordance with Rule 103 of Regulation M, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the securities. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security. If all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

Underwriters and their affiliates may be customers of, engage in transactions with or perform services for us or our affiliates in the ordinary course of business.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in one business day, unless the parties to any such trade expressly agree otherwise or the securities are sold by us to an underwriter in a firm commitment underwritten offering. The applicable prospectus supplement may provide that the original issue date for your securities may be more than one scheduled business day after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than one business day after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock, together with any additional information we include in any applicable prospectus supplements or any free writing prospectuses that we may authorize to be delivered to you, summarizes the material terms and provisions of our capital stock that we may offer under this prospectus. While the terms we have summarized below will apply generally to any future capital stock that we may offer, we will describe the particular terms of any class or series of these securities in more detail in the applicable prospectus supplement or free writing prospectus. This description is only a summary. For the complete terms of our capital stock, please refer to our amended and restated certificate of incorporation (as amended, our “Certificate of Incorporation”) and our third amended and restated bylaws (as amended, our “Bylaws”), that are incorporated by reference into the registration statement, of which this prospectus forms a part. The terms of these securities may also be affected by the Delaware General Corporation Law (the “DGCL”). The summary below and any summary contained in any prospectus supplement or free writing prospectus are qualified in their entirety by reference to our Certificate of Incorporation and our Bylaws.

Common Stock

We are authorized to issue 195,000,000 shares of common stock, par value $0.001 per share, of which 170,329,158 shares were issued and outstanding as of February 20, 2026. The holders of common stock possess exclusive voting rights in us, except to the extent our board of directors specifies voting power with respect to any other class of securities issued in the future. Each holder of our common stock is entitled to one vote for each share held of record on each matter submitted to a vote of stockholders, including the election of directors. Stockholders do not have any right to cumulate votes in the election of directors.

Subject to preferences that may be granted to the holders of preferred stock, each holder of our common stock is entitled to share ratably in distributions to stockholders and to receive ratably such dividends as may be declared by our board of directors out of funds legally available therefor. In the event of our liquidation, dissolution or winding up, the holders of our common stock will be entitled to receive, after payment of all of our debts and liabilities and of all sums to which holders of any preferred stock may be entitled, the distribution of any of our remaining assets. Holders of our common stock have no conversion, exchange, sinking fund, redemption or appraisal rights (other than as may be determined by our board of directors in its sole discretion) and have no preemptive rights to subscribe for any of our securities.

All of the outstanding shares of our common stock are, and the shares of common stock issued upon the conversion of any securities convertible into our common stock will be, fully paid and non-assessable. The shares of common stock offered by this prospectus or upon the conversion of any preferred stock or debt securities or exercise of any warrants offered pursuant to this prospectus, when issued and paid for, will also be, fully paid and non-assessable.

Our common stock is listed on The Nasdaq Global Select Market under the symbol “KTOS.”

Undesignated Preferred Stock

We are authorized to issue 5,000,000 shares of preferred stock, par value $0.001 per share, none of which were issued and outstanding as of February 26, 2026. Our board of directors is authorized to classify or reclassify any unissued portion of our authorized shares of preferred stock to provide for the issuance of shares of other classes or series, including preferred stock in one or more series. We may issue preferred stock from time to time in one or more classes or series, with the exact terms of each class or series established by our board of directors. Without seeking stockholder approval, our board of directors may issue preferred stock with voting and other rights that could adversely affect the voting power of the holders of our common stock. Additionally, the issuance of preferred stock may have the effect of decreasing the market price of the common stock.

The rights, preferences, privileges and restrictions of the preferred stock of each series will be fixed by the certificate of designation relating to each series. A prospectus supplement relating to each series will specify the terms of the preferred stock, including, but not limited to:

•the distinctive designation and the maximum number of shares in the series;

•the terms on which dividends, if any, will be paid;

•the voting rights, if any, on the shares of the series;

•the terms and conditions, if any, on which the shares of the series shall be convertible into, or exchangeable for, shares of any other class or classes of capital stock;

•the terms on which the shares may be redeemed, if at all;

•the liquidation preference, if any; and

•any or all other preferences, rights, restrictions, including restrictions on transferability, and qualifications of shares of the series.

The issuance of preferred stock may delay, deter or prevent a change in control.

We will describe the specific terms of a particular series of preferred stock in the prospectus supplement relating to that series. The description of preferred stock above and the description of the terms of a particular series of preferred stock in the prospectus supplement are not complete. You should refer to the applicable certificate of designation for complete information. The applicable prospectus supplement will contain a description of U.S. federal income tax consequences relating to the preferred stock.

Possible Anti-Takeover Effects of Delaware Law and our Charter Documents

Provisions of the DGCL and our Certificate of Incorporation and Bylaws could make it more difficult to acquire us by means of a tender offer, a proxy contest or otherwise, or to remove incumbent officers and directors. These provisions, summarized below, are expected to discourage certain types of coercive takeover practices and takeover bids that our board of directors may consider inadequate and to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of increased protection of our ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging takeover or acquisition proposals because, among other things, negotiation of these proposals could result in an improvement of their terms.

Delaware Anti-Takeover Statute

We are subject to Section 203 of the DGCL, an anti-takeover statute. In general, Section 203 of the DGCL prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a period of three years following the time the person became an interested stockholder, unless the business combination or the acquisition of shares that resulted in a stockholder becoming an interested stockholder is approved in a prescribed manner. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. Generally, an “interested stockholder” is a person who, together with affiliates and associates, owns (or within three years prior to the determination of interested stockholder status did own) 15% or more of the applicable corporation’s voting stock. The existence of this provision would be expected to have an anti-takeover effect with respect to transactions not approved in advance by our board of directors, including discouraging attempts that might result in a premium over the market price for the shares of common stock held by our stockholders.

Election and Removal of Directors

Our board of directors is elected annually by all holders of our capital stock. To be eligible for election or appointment to the board of directors, an individual must meet certain director qualification requirements set forth in our Bylaws. At a special meeting of stockholders, directors may be removed without cause by the affirmative vote of the holders of at least a majority of the outstanding shares entitled to vote on such removal.

Amendment

The affirmative vote of the holders of at least 66 2/3 % of the voting power of all of the then-outstanding shares of our voting stock, voting together as a single class, is required to, among other things, alter, amend or repeal certain provisions of our Certificate of Incorporation, including those related to the election and removal of the board of directors, amendment of our Bylaws and Certificate of Incorporation, restrictions against stockholder actions by written consent and the indemnification of officers and directors.

Our Bylaws, may only be amended (or new bylaws adopted) by the board of directors or the affirmative vote of the holders of at least 66 2/3 % of the voting power of all of the then-outstanding shares of our voting stock.

Size of Board and Vacancies

Pursuant to our Certificate of Incorporation and our Bylaws, our board of directors has the exclusive right to fix the size of the board and to fill any vacancies resulting from death, resignation, disqualification or removal as well as any newly created directorships arising from an increase in the size of the board of directors.

Special Stockholder Meetings

Our Bylaws provide that only a majority of the total number of directors then in office may call a special meeting of the stockholders, and any business conducted at any special meeting must have been properly brought before the meeting. To be properly brought before a meeting, business must be specified in the notice of meeting (or any supplement thereto) given by or at the direction of our board of directors, otherwise properly brought before the meeting by or at the direction of our board of directors, or otherwise properly brought before the meeting by a stockholder, but, in the case of a special meeting, if and only if the notice of the meeting provides for business to be brought before the meeting by a stockholder.

Stockholder Action by Unanimous Written Consent

Our Certificate of Incorporation expressly eliminates the right of our stockholders to act by written consent. Stockholder action must take place at the annual or a special meeting of our stockholders.

Requirements for Advance Notification of Stockholder Nominations and Proposals

Our Bylaws establish advance notice procedures with respect to stockholder proposals and nomination of candidates for election as directors other than nominations made by or at the direction of our board of directors or a committee of our board of directors.

No Cumulative Voting

The DGCL provides that stockholders are denied the right to cumulate votes in the election of directors unless a company's Certificate of Incorporation provides otherwise. Our Certificate of Incorporation does not provide for cumulative voting.

Undesignated Preferred Stock

The authority that will be possessed by our board of directors to issue preferred stock could potentially be used to discourage attempts by third parties to obtain control of the Company through a merger, tender offer, proxy contest or otherwise by making such attempts more difficult or more costly. Our board of directors may issue preferred stock with voting rights or conversion rights that, if exercised, could adversely affect the voting power of the holders of our common stock.

Authorized but Unissued Shares

Our authorized but unissued shares of common stock and preferred stock will be available for future issuance without stockholder approval. We may use additional shares for a variety of purposes, including future public offerings to raise additional capital, to fund acquisitions and as employee compensation. The existence of authorized but unissued shares of common stock and preferred stock could render more difficult or discourage an attempt to obtain control of us by means of a proxy contest, tender offer, merger or otherwise.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is EQ Shareowner Services. Its address is 1110 Centre Pointe Curve, Suite 101, Mendota Heights, MN 55120 and its telephone number is (800) 468-9716. The transfer agent for any series of preferred stock that we may offer under this prospectus will be named and described in the prospectus supplement for that series.

DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplements or free writing prospectuses, summarizes the material terms and provisions of the debt securities that we may offer under this prospectus. We may issue an unlimited amount of debt securities, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any future debt securities we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement or free writing prospectus. The terms of any debt securities we offer under a prospectus supplement may differ from the terms we describe below. Unless the context requires otherwise, whenever we refer to the “indentures,” we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue any senior debt securities under the senior indenture and any supplemental indentures that we will enter into with the trustee named in the senior indenture. We will issue any subordinated debt securities under the subordinated indenture and any supplemental indentures that we will enter into with the trustee named in the subordinated indenture. We have filed forms of these documents as exhibits to the registration statement, of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The indentures will be qualified under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). We use the term “trustee” to refer to either the trustee under the senior indenture or the trustee under the subordinated indenture, as applicable.

The following summaries of material provisions of the senior debt securities, the subordinated debt securities and the applicable indentures are subject to, and qualified in their entirety by reference to, all of the provisions of the indenture and any supplemental indentures applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indentures and supplemental indentures that contain the terms of the debt securities.

The terms of each series of debt securities will be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in an officers’ certificate or by a supplemental indenture. Debt securities may be issued in separate series without limitation as to aggregate principal amount. We may specify a maximum aggregate principal amount for the debt securities of any series. We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

•the title;

•the principal amount being offered, and if a series, the total amount authorized and the total amount outstanding;

•any limit on the amount that may be issued;

•whether or not we will issue the series of debt securities in global form, and, if so, the terms and who the depositary will be;

•the maturity date;

•whether and under what circumstances, if any, we will pay additional amounts on any debt securities held by a person who is not a U.S. person for tax purposes, and whether we can redeem the debt securities if we have to pay such additional amounts;

•the annual interest rate, which may be fixed or variable, or the method for determining the rate and the date interest will begin to accrue, the dates interest will be payable and the regular record dates for interest payment dates or the method for determining such dates;

•whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

•the terms of the subordination of any series of subordinated debt;

•the place where payments will be payable;

•restrictions on transfer, sale or other assignment, if any;

•our right, if any, to defer payment of interest and the maximum length of any such deferral period;

•the date, if any, after which, and the price at which, we may, at our option, redeem the series of debt securities pursuant to any optional or provisional redemption provisions and the terms of those redemption provisions;

•provisions for a sinking fund purchase or other analogous fund, if any, including the date, if any, on which, and the price at which we are obligated, pursuant thereto or otherwise, to redeem, or at the holder’s option, to purchase, the series of debt securities and the currency or currency unit in which the debt securities are payable;

•whether the applicable indenture will restrict our ability or the ability of our subsidiaries to:

•incur additional indebtedness;

•issue additional securities;

•create liens;

•pay dividends or make distributions in respect of our capital stock or the capital stock of our subsidiaries;

•redeem capital stock;

•place restrictions on our subsidiaries’ ability to pay dividends, make distributions or transfer assets;

•make investments or other restricted payments;

•sell, transfer or otherwise dispose of assets;

•enter into sale-leaseback transactions;

•engage in transactions with stockholders or affiliates;

•issue or sell stock of our subsidiaries; or

•effect a consolidation or merger;

•whether the indenture will require us to maintain any interest coverage, fixed charge, cash flow-based, asset-based or other financial ratios;

•information describing any book-entry features;

•the applicability of the provisions in the indenture on discharge;

•whether the debt securities are to be offered at a price such that they will be deemed to be offered at an “original issue discount” as defined in paragraph (a) of Section 1273 of the Internal Revenue Code of 1986, as amended;

•the denominations in which we will issue the series of debt securities, if other than denominations of $2,000 and any integral multiple of $1,000 in excess thereof;

•the currency of payment of debt securities if other than U.S. dollars and the manner of determining the equivalent amount in U.S. dollars; and

•any other specific terms, preferences, rights or limitations of, or restrictions on, the debt securities, including any additional events of default or covenants provided with respect to the debt securities, and any terms that may be required by us or advisable under applicable laws or regulations.

U.S. federal income tax consequences related to the debt securities, including tax consequences applicable to debt securities sold at an original issue discount, will be described in the applicable prospectus supplement. In addition, U.S. federal income tax or other consequences applicable to any debt securities which are denominated in a currency or currency unit other than U.S. dollars may be described in the applicable prospectus supplement.

Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms under which a series of debt securities may be convertible into or exchangeable for our common stock, our preferred stock or other securities (including securities of a third party). We will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock, our preferred stock or other securities (including securities of a third party) that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indentures will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or

otherwise dispose of all or substantially all of our assets. However, any successor to or acquiror of such assets must assume all of our obligations under the indentures or the debt securities, as appropriate. If the debt securities are convertible into or exchangeable for our other securities or securities of third parties, the person with whom we consolidate or merge or to whom we sell all of our property must make provisions for the conversion of the debt securities into securities that the holders of the debt securities would have received if they had converted the debt securities before the consolidation, merger or sale.

Events of Default under an Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indentures with respect to any series of debt securities that we may issue:

•if we fail to pay interest when due and payable and our failure continues for 30 days;

•if we fail to pay the principal, premium or sinking fund payment, if any, when due and payable;

•if we fail to observe or perform any other covenant contained in the debt securities or the indentures, other than a covenant specifically relating to another series of debt securities, and our failure continues for 90 days after we receive notice from the trustee or we and the trustee receive notice from the holders of at least 25% in aggregate principal amount of the outstanding debt securities of the applicable series; and

•if specified events of bankruptcy, insolvency or reorganization occur.

We will describe in each applicable prospectus supplement any additional events of default relating to the relevant series of debt securities. If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the applicable trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the applicable trustee if notice is given by such holders, may declare the unpaid principal, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default arises due to the occurrence of certain specified bankruptcy, insolvency or reorganization events, the unpaid principal, premium, if any, and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder of such debt securities.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any such waiver shall cure the default or event of default.

Subject to the terms of the applicable indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity or security satisfactory to it against any loss, liability or expense. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

•the direction so given by the holder is not in conflict with any law or the applicable indenture; and

•subject to its duties under the Trust Indenture Act, the trustee need not take any action that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.

The indentures provide that if an event of default has occurred and is continuing, the trustee will be required in the exercise of its powers to use the degree of care that a prudent person would use in the conduct of its own affairs. The trustee, however, may refuse to follow any direction that conflicts with law or the indenture, or that the trustee determines is unduly prejudicial to the rights of any other holder of the relevant series of debt securities, or that would involve the trustee in personal liability. Prior to taking any action under the indentures, the trustee will be entitled to indemnification against all costs, expenses and liabilities that would be incurred by taking or not taking such action.

A holder of the debt securities of any series will have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies only if:

•the holder has given written notice to the trustee of a continuing event of default with respect to that series;

•the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series have made a written request and such holders have offered reasonable indemnity to the trustee or security satisfactory to it against any loss, liability or expense to be incurred in compliance with instituting the proceeding as trustee; and

•the trustee does not institute the proceeding, and does not receive from the holders of a majority in aggregate principal amount of the outstanding debt securities of that series other conflicting directions within 60 days after the notice, request and offer.

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indentures.

The indentures provide that if a default occurs and is continuing and is actually known to a responsible officer of the trustee, the trustee must mail to each holder notice of the default within 45 days after it occurs, unless such default has been cured. Except in the case of a default in the payment of principal or premium of, or interest on, any debt security or certain other defaults specified in the applicable indenture, the trustee shall be protected in withholding such notice if and so long as the board of directors, the executive committee or another committee of directors, or responsible officers of the trustee, in good faith determine that withholding notice is in the best interests of holders of the relevant series of debt securities.

Modification of Indenture; Waiver

Subject to the terms of the applicable indenture for any series of debt securities that we may issue, we and the trustee may modify or amend an indenture without the consent of any holders of the applicable debt securities with respect to the following specific matters:

•to fix any ambiguity, defect or inconsistency in the indenture;

•to comply with the provisions described above under “-Consolidation, Merger or Sale;”

•to comply with any requirements of the SEC in connection with the qualification of any indenture under the Trust Indenture Act;

•to add to, delete from or revise the conditions, limitations and restrictions on the authorized amount, terms or purposes of issue, authentication and delivery of debt securities, as set forth in such indenture;

•to provide for the issuance of, and establish the form and terms and conditions of, the debt securities of any series as provided above under “-General,” to establish the form of any certifications required to be furnished pursuant to the terms of the indenture or any series of debt securities, or to add to the rights of the holders of any series of debt securities;

•to evidence and provide for the acceptance of appointment hereunder by a successor trustee or other agent;

•to comply with the applicable procedures of the applicable depositary;

•to provide for uncertificated debt securities in addition to or in place of certificated debt securities and to make all appropriate changes for such purpose;

•to secure debt securities of any series;

•to add such new covenants, restrictions, conditions or provisions for the protection of the holders, and to make the occurrence, or the occurrence and the continuance, of a default in any such additional covenants, restrictions, conditions or provisions an event of default or to surrender any right or power conferred to us in the indenture; or

•to change anything that does not materially adversely affect the interests of any holder of debt securities of any series in any material respect; provided that any amendment made solely to conform the provisions of the indenture to the corresponding description of the debt securities contained in the applicable prospectus or prospectus supplement shall be deemed not to adversely affect the interests of the holders of such debt

securities; provided further, that in connection with any such amendment we will provide the trustee with an officers’ certificate certifying that such amendment will not adversely affect the rights or interests of the holders of such debt securities.

In addition, under the indentures, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may only make the following changes to the applicable indenture with the consent of each holder of any outstanding debt securities affected:

•extending the fixed maturity of the series of debt securities;

•reducing the principal amount, reducing the rate of or extending the time of payment of interest, or reducing any premium payable upon the redemption of any debt securities;

•reducing the percentage of debt securities, the holders of which are required to consent to any amendment, supplement, modification or waiver of such indenture;

•changing any of our obligations to pay additional amounts;

•reducing the amount of principal of an original issue discount security or any other note payable upon acceleration of the maturity thereof;

•changing the currency in which any note or any premium or interest is payable;

•impairing the right to enforce any payment on or with respect to any note;

•adversely changing the right to convert or exchange such series of debt securities, including decreasing the conversion rate or increasing the conversion price of, such debt securities, if applicable;

•in the case of the subordinated indenture, modifying the subordination provisions in a manner adverse to the holders of the subordinated debt securities;

•if the debt securities are secured, changing the terms and conditions pursuant to which the debt securities are secured in a manner adverse to the holders of the secured debt securities;

•reducing the requirements contained in the applicable indenture for quorum or voting;

•changing any of our obligations to maintain an office or agency in the places and for the purposes required by the applicable indenture; or

•modifying any of the above provisions described in this paragraph.

Discharge

Each indenture provides that, subject to the terms of such indenture and any limitation otherwise provided in the prospectus supplement applicable to a particular series of debt securities, we may elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

•register the transfer or exchange of debt securities of such series;

•replace stolen, lost or mutilated debt securities of such series;

•maintain paying agents;

•hold monies for payment in trust;

•recover excess money held by the trustee;

•compensate and indemnify the trustee; and

•appoint any successor trustee.

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, and any premium and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we otherwise specify in the applicable prospectus supplement, in denominations of $2,000 and any integral multiple of $1,000 in excess thereof. The indentures provide that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository

Trust Company or another depositary named by us and identified in a prospectus supplement with respect to that series. See “Legal Ownership of Securities” below for a further description of the terms relating to any book-entry securities.

At the option of the holder, subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange such debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indentures and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of debt securities may present such debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, or the indenture governing the terms of such debt securities, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem debt securities of any series, we will not be required to:

•issue, register the transfer of, or exchange any debt securities of that series during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

•register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.

Information Concerning the Trustee

The applicable trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture and is under no obligation to exercise any of the powers given it by the indentures at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur. However, upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs.

Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest payment.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee in the City of New York as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indentures and the debt securities will be governed by and construed in accordance with the laws of the State of New York.

Ranking of Debt Securities

The subordinated debt securities will be unsecured and will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in the applicable prospectus supplement. The subordinated indenture does not limit the amount of subordinated debt securities that we may issue. It also does not limit us from issuing any other secured or unsecured debt.

The senior debt securities will be unsecured and will rank equally in right of payment with all our other senior unsecured debt. The senior indenture does not limit the amount of senior debt securities that we may issue. It also does not limit us from issuing any other secured or unsecured debt.

DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements and any applicable free writing prospectuses, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series. Warrants may be offered independently or together with common stock, preferred stock or debt securities offered by any prospectus supplement, and may be attached to or separate from those securities. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants that we may offer in more detail in the applicable prospectus supplement and any applicable free writing prospectus. The terms of any warrants offered under a prospectus supplement may differ from the terms described below. However, no prospectus supplement will fundamentally change the terms that are set forth in this prospectus or offer a security that is not registered and described in this prospectus at the time of its effectiveness.

We will issue the warrants under a warrant agreement that we will enter into with a warrant agent to be selected by us. The warrant agent will act solely as an agent of ours in connection with the warrants and will not act as an agent for the holders or beneficial owners of the warrants. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a Current Report on Form 8-K that we file with the SEC, the form of warrant agreement, including a form of warrant certificate, that describes the terms of the particular series of warrants we are offering before the issuance of the related series of warrants. The following summaries of material provisions of the warrants and the warrant agreements are subject to, and qualified in their entirety by reference to, all the provisions of the warrant agreement and warrant certificate applicable to a particular series of warrants. We urge you to read the applicable prospectus supplement and any applicable free writing prospectus related to the particular series of warrants that we sell under this prospectus, as well as the complete warrant agreements and warrant certificates that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms relating to a series of warrants, including:

•the offering price and aggregate number of warrants offered;

•the currency for which the warrants may be purchased;

•if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each such security or each principal amount of such security;

•if applicable, the date on and after which the warrants and the related securities will be separately transferable;

•in the case of warrants to purchase debt securities, the principal amount of debt securities purchasable upon exercise of one warrant and the price at, and currency in which, this principal amount of debt securities may be purchased upon such exercise;

•in the case of warrants to purchase common stock or preferred stock, the number of shares of common stock or preferred stock, as the case may be, purchasable upon the exercise of one warrant and the price at which these shares may be purchased upon such exercise;

•the effect of any merger, consolidation, sale or other disposition of our business on the warrant agreements and the warrants;

•the terms of any rights to redeem or call the warrants;

•any provisions for changes to or adjustments in the exercise price or number of securities issuable upon exercise of the warrants;

•the dates on which the right to exercise the warrants will commence and expire;

•the manner in which the warrant agreements and warrants may be modified;

•the material United States federal income tax consequences of holding or exercising the warrants;

•the terms of the securities issuable upon exercise of the warrants; and

•any other specific terms, preferences, rights or limitations of or restrictions on the warrants.

Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

•in the case of warrants to purchase debt securities, the right to receive payments of principal of, or premium, if any, or interest on, the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture; or

•in the case of warrants to purchase common stock or preferred stock, the right to receive dividends, if any, or, payments upon our liquidation, dissolution or winding up or to exercise voting rights, if any.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Holders of the warrants may exercise the warrants by delivering the warrant certificate representing the warrants to be exercised together with specified information, and paying the required amount to the warrant agent in immediately available funds, as provided in the applicable prospectus supplement. We will set forth on the reverse side of the warrant certificate and in the applicable prospectus supplement the information that the holder of the warrant will be required to deliver to the warrant agent.

Upon receipt of the required payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will issue and deliver the securities purchasable upon such exercise. If fewer than all of the warrants represented by the warrant certificate are exercised, then we will issue a new warrant certificate for the remaining amount of warrants. If we so indicate in the applicable prospectus supplement, holders of the warrants may surrender securities as all or part of the exercise price for warrants.

Enforceability of Rights by Holders of Warrants

Each warrant agent will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

DESCRIPTION OF RIGHTS

General

We may issue rights to purchase common stock, preferred stock or the other securities described in this prospectus. This prospectus, any accompanying prospectus supplement, and any applicable free writing prospectus will contain the material terms and conditions for each right. The accompanying prospectus supplement may add, update or change the terms and conditions of the rights as described in this prospectus.

We will describe in the applicable prospectus supplement the terms and conditions of the issue of rights being offered, the rights agreement relating to the rights and the rights certificates representing the rights, including, as applicable:

•the title of the rights;

•the date of determining the stockholders entitled to the rights distribution;

•the title, aggregate number of shares of common stock, preferred stock or other securities purchasable upon exercise of the rights;

•the exercise price;

•the currencies in which the rights are being offered;

•the aggregate number of rights issued;

•the date, if any, on and after which the rights will be separately transferable;

•the date on which the right to exercise the rights will commence and the date on which the right will expire; and

•any other terms of the rights, including terms, procedures and limitations relating to the distribution, exchange and exercise of the rights.

Exercise of Rights

Each right will entitle the holder of rights to purchase for cash the principal amount of shares of common stock, preferred stock or other securities at the exercise price provided in the applicable prospectus supplement. Rights may be exercised at any time up to the close of business on the expiration date for the rights provided in the applicable prospectus supplement. After the close of business on the expiration date, all unexercised rights will be void.

Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment and the rights certificate properly completed and duly executed at the corporate trust office of the rights agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of common stock, preferred stock, or other securities purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters, brokers or dealers or through a combination of such methods, including pursuant to standby underwriting arrangements, as described in the applicable prospectus supplement.

DESCRIPTION OF UNITS

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a Current Report on Form 8-K that we file with the SEC, the form of unit agreement that describes the terms of the series of units we are offering, and any supplemental agreements, before the issuance of the related series of units. The following summaries of material terms and provisions of the units are subject to, and qualified in their entirety by reference to, all the provisions of the unit agreement and any supplemental agreements applicable to a particular series of units. We urge you to read the applicable prospectus supplements related to the particular series of units that we sell under this prospectus, as well as the complete unit agreement and any supplemental agreements that contain the terms of the units.

General

We may issue units comprised of one or more debt securities, shares of common stock, shares of preferred stock, warrants or rights in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date.

We will describe in the applicable prospectus supplement the terms of the series of units, including:

•the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

•any provisions of the governing unit agreement that differ from those described in this prospectus; and

•any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units.

The provisions described in this section, as well as those described under “Description of Capital Stock,” “Description of Debt Securities,” “Description of Warrants” and “Description of Rights” will apply to each unit and to any common stock, preferred stock, debt security, warrant or right included in each unit, respectively.

Issuance in Series

We may issue units in such amounts and in any number of distinct series as we determine.

Enforceability of Rights by Holders of Units

Each unit agent will act solely as our agent under the applicable unit agreement and will not assume any obligation or relationship of agency or trust with any holder of any unit. A single bank or trust company may act as unit agent for more than one series of units. A unit agent will have no duty or responsibility in case of any default by us under the applicable unit agreement or any security included in such unit, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a unit may, without the consent of the related unit agent or the holder of any other unit, enforce by appropriate legal action its rights as holder under any security included in the unit.

We, the unit agents and any of their agents may treat the registered holder of any unit certificate as an absolute owner of the units evidenced by that certificate for any purpose and as the person entitled to exercise the rights attaching to the units so requested, despite any notice to the contrary. See “Legal Ownership of Securities.”

LEGAL OWNERSHIP OF SECURITIES

We can issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary, warrant agent or other agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as will be specified in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Global securities will be registered in the name of the depositary. Consequently, for global securities, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities we may offer.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not legal holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities that are not issued in global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any such trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not legal holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee, agent or third party employed by us or a trustee or any agents, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with its participants or customers or by law, to

pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of an indenture, or for other purposes. In such an event, we would seek approval only from the legal holders, and not the indirect holders, of the securities. Whether and how the legal holders contact the indirect holders is up to the legal holders.

When we refer to “you” in this prospectus, we mean those who invest in the securities being offered by this prospectus, whether they are the holders or only indirect holders of those securities. When we refer to “your securities” in this prospectus, we mean the securities in which you will hold a direct or indirect interest.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form because the securities are represented by one or more global securities or in street name, you should check with your own institution to find out:

•how it handles securities payments and notices;

•whether it imposes fees or charges;

•how it would handle a request for the holders’ consent, if ever required;

•whether and how you can instruct it to send you securities registered in your own name so you can be a legal holder, if that is permitted in the future;

•how it would exercise rights under the securities if there were a default or other event triggering the need for holders to act to protect their interests; and

•if the securities are in book-entry form, how the depositary’s rules and procedures will affect these matters.

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company (“DTC”) will be the depositary for all securities we issue in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “-Special Situations When A Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and legal holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in such global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a legal holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued as a global security, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

Special Considerations For Global Securities

As an indirect holder, an investor’s rights relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only as global securities, an investor should be aware of the following:

•an investor cannot cause the securities to be registered in his or her name, and cannot obtain non-global certificates for his or her interest in the securities, except in the special situations we describe below;

•an investor will be an indirect holder and must look to his or her own bank or broker for payments on the securities and protection of his or her legal rights relating to the securities, as we describe above;

•an investor may not be able to sell interests in the securities to some insurance companies and to other institutions that are required by law to own their securities in non-book-entry form;

•an investor may not be able to pledge his or her interest in the global security in circumstances where certificates representing the securities must be delivered to the lender or other beneficiary of the pledge in order for the pledge to be effective;

•the depositary’s policies, which may change from time to time, will govern payments, transfers, exchanges and other matters relating to an investor’s interest in the global security. We and any applicable trustee have no responsibility for any aspect of the depositary’s actions or for its records of ownership interests in the global security. We and the trustee also do not supervise the depositary in any way;

•the depositary may, and we understand that DTC will, require that those who purchase and sell interests in the global security within its book-entry system use immediately available funds, and your broker or bank may require you to do so as well; and

•financial institutions that participate in the depositary’s book-entry system, and through which an investor holds its interest in the global security, may also have their own policies affecting payments, notices and other matters relating to the securities. There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When A Global Security Will Be Terminated

In a few special situations described below, a global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own names, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, a global security will terminate when the following special situations occur:

•if the depositary notifies us that it is unwilling, unable or no longer qualified to continue as depositary for that global security and we do not appoint another institution to act as depositary within 90 days;

•if we notify any applicable trustee that we wish to terminate that global security; or

•if an event of default has occurred with regard to securities represented by that global security and has not been cured or waived.

The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the prospectus supplement. If a global security is terminated, only the depositary, and not we, the trustee, the agent or other third party, as applicable, is responsible for deciding the names of the institutions in whose names the securities represented by the global security will be registered and, therefore, who will be the direct holders of those securities.

LEGAL MATTERS

Sheppard, Mullin, Richter & Hampton LLP, Menlo Park, California will pass for us upon the validity of the securities being offered by this prospectus. If the securities are being distributed in an underwritten offering, certain legal matters will be passed upon for the underwriters by counsel identified in the related prospectus supplement.

EXPERTS

The financial statements of the Company incorporated by reference in this prospectus, and the effectiveness of the Company’s internal control over financial reporting have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report. Such financial statements are incorporated by reference in reliance upon the report of such firm, given their authority as experts in accounting and auditing.

WHERE YOU CAN FIND ADDITIONAL INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains an Internet website at http://www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC, including Kratos. You may also access our reports and proxy statements free of charge at our Internet website, http://www.kratosdefense.com. The information contained in, or that can be accessed through, our website is not part of this prospectus. The prospectus included in this filing is part of a registration statement filed by us with the SEC. The full registration statement can be obtained from the SEC, as indicated above, or from us by writing to the address listed under “Incorporation of Certain Information by Reference” below.

This prospectus is part of a registration statement that we have filed with the SEC relating to the securities to be offered. This prospectus does not contain all of the information we have included in the registration statement and the accompanying exhibits and schedules in accordance with the rules and regulations of the SEC, and we refer you to the omitted information. The statements this prospectus makes pertaining to the content of any contract, agreement or other document that is an exhibit to the registration statement necessarily are summaries of their material provisions and do not describe all exceptions and qualifications contained in those contracts, agreements or documents. You should read those contracts, agreements or documents for information that may be important to you. The registration statement, exhibits and schedules are available at the SEC’s Internet website.

You should rely only on information in this prospectus or incorporated by reference herein. We have not authorized any person to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus is accurate as of any date other than the date of the front page of this prospectus, regardless of the time of delivery of this prospectus or any sale of the securities offered by this prospectus.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference the information we file with it, which means that we can disclose important information to you by referring you to another document that we have filed separately with the SEC. The information incorporated by reference is considered to be a part of this prospectus. We hereby incorporate by reference the following information or documents into this prospectus:

•our Annual Report on Form 10-K for the fiscal year ended December 28, 2025 filed with the SEC on February 23, 2026; and

•the portions of our Definitive Proxy Statement filed with the SEC on April 4, 2025, incorporated by reference into the Annual Report on Form 10-K for the fiscal year ended December 29, 2024; and

Any information in any of the foregoing documents will automatically be deemed to be modified or superseded to the extent that information in this prospectus or in a later filed document that is incorporated or deemed to be incorporated herein by reference modifies or replaces such information. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

We also incorporate by reference any future filings (other than information in current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, until the termination of the offering of the securities covered by this prospectus. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

Upon written or oral request, we will provide to you, without charge, a copy of any or all of the documents that are incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits which are specifically incorporated by reference into such documents. Requests should be directed to: Kratos Defense & Security Solutions, Inc., Attention: Investor Relations, 10680 Treena St., Suite 600, San Diego, California 92131, telephone (858) 812-7300.

14,768 Shares

Kratos Defense & Security Solutions, Inc.

Common Stock

Prospectus supplement

SEC Form 424B3 filed by Kratos Defense & Security Solutions Inc.