Nuveen Taxable Municipal Income Fund

Closed‑End Funds

March 31, 2025

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES


Investment Company Act file number		811‑22391

Nuveen Taxable Municipal Income Fund

(Exact name of registrant as specified in charter)

Nuveen Investments

333 West Wacker Drive

Chicago, Illinois 60606

(Address of principal executive offices) (Zip code)

Mark L. Winget

Vice President and Secretary

333 West Wacker Drive

Chicago, Illinois 60606

(Name and address of agent for service)

Registrant’s telephone number, including area code: (800) 257‑8787

Date of fiscal year end: March 31

Date of reporting period: March 31, 2025

Item 1.

Reports to Stockholders.

Nuveen Municipal

Closed-End Funds



Nuveen Taxable Municipal Income Fund			NBB

Annual

Report

Table

of Contents


Important Notices			3

Discussion of Fund Performance			4

Common Share Information			6

About the Fund’s Benchmark			8

Fund Performance, Leverage and Holdings Summaries			9

Report of Independent Registered Public Accounting Firm			12

Portfolio of Investments			13

Statement of Assets and Liabilities			22

Statement of Operations			23

Statement of Changes in Net Assets			24

Statement of Cash Flows			25

Financial Highlights			26

Notes to Financial Statements			28

Shareholder Update			39

Important Tax Information			59

Shareholder Meeting Report			60

Additional Fund Information			61

Glossary of Terms Used in this Report			62

Board Members & Officers			63

Important Notices

Management fees: As of May 1, 2024, the Fund’s overall complex-level fee begins at a maximum rate of 0.1600% of the Fund’s average daily net assets, with breakpoints for eligible complex-level assets above $124.3 billion.

Discussion of

Fund Performance

Nuveen Taxable Municipal Income Fund (NBB)

Nuveen Asset Management, LLC (NAM), an affiliate of Nuveen Fund Advisors, LLC, is the investment adviser for the Nuveen Taxable Municipal Income Fund (NBB).

The portfolio managers for NBB are Daniel Close, CFA, and Kristen DeJong, CFA

Below is a discussion of the Fund’s performance and the factors that contributed and detracted during the 12-month reporting period ended March 31, 2025. For more information on Fund investment objectives and policies, please refer to the Shareholder Update section at the end of the report.

Nuveen Taxable Municipal Income Fund (NBB)

What factors affected markets during the reporting period?

•

Municipal bond yields rose over the reporting period, except for short maturities, whose yields fell. However, the path was not a straight line given uncertainties about the Federal Reserve’s plan for monetary easing, U.S. fiscal policy under the Trump administration and the impact to the economy and inflation.

•

Credit fundamentals remained strong, with default activity at low levels. Although supply increased during the reporting period, demand for municipal debt remained solid.

What key strategies were used to manage the Fund during the reporting period?

•

The Fund’s trading activity remained focused on pursuing its investment objectives. There were no material changes to the Fund’s positioning.

•

The portfolio management team engaged in opportunistic trades to support the Fund’s income by reinvesting premiums received as part of the Fund’s hedging program as well as bond calls and maturities across a variety of sectors.

How did the Fund perform and what factors affected relative performance?

For the 12-month reporting period ended March 31, 2025, NBB returned 4.79%. The Fund outperformed the Bloomberg Taxable Municipal Long Bond Index, which returned 3.66%.

Top contributors to relative performance

•

Overweight allocations to BB-rated and non-rated bonds.

•

Underweight to durations of 12 years and longer and overweight to durations of four to eight years.

•

The Fund’s interest rate hedge position through the use of futures and swaps.

Top detractors from relative performance

•

Overweight allocations to the water and sewer sector and the electric sector.

•

Underweight to durations of eight to 10 years.

This material is not intended to be a recommendation or investment advice, does not constitute a solicitation to buy, sell or hold a security or an investment strategy, and is not provided in a fiduciary capacity. The information provided does not take into account the specific objectives or circumstances of any particular investor, or suggest any specific course of action. Investment decisions should be made based on an investor’s objectives and circumstances and in consultation with his or her advisors.

Certain statements in this report are forward-looking statements. Discussions of specific investments are for illustration only and are not intended as recommendations of individual investments. The forward-looking statements and other views expressed herein are those of the portfolio managers as of the date of this report. Actual future results or occurrences may differ significantly from those anticipated in any forward-looking statements, and the views expressed herein are subject to change at any time, due to numerous market and other factors. The Fund disclaims any obligation to update publicly or revise any forward-looking statements or views expressed herein.

For financial reporting purposes, the ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s Group (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc. (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A and BBB are investment grade ratings, while BB, B, CCC, CC, C and D are below investment grade ratings. Holdings designated N/R are not rated by these national rating agencies.

Bond insurance guarantees only the payment of principal and interest on the bond when due, and not the value of the bonds themselves, which will fluctuate with the bond market and the financial success of the issuer and the insurer. Insurance relates specifically to the bonds in the portfolio and not to the share prices of a Fund. No representation is made as to the insurers’ ability to meet their commitments.

Refer to the Glossary of Terms Used in this Report for further definition of the terms used within this section.

Common Share Information

COMMON SHARE DISTRIBUTION INFORMATION

The following information regarding the Fund’s distributions is current as of March 31, 2025. The Fund’s distribution levels may vary over time based on the Fund’s investment activity and portfolio investments value changes.

During the current reporting period, the Fund’s distributions to common shareholders were as shown in the accompanying table.


	Per Common Share Amounts
Monthly Distributions (Ex-Dividend Date)	NBB

April		$0.0735
May		0.0735
June		0.0965
July		0.0965
August		0.0965
September		0.0965
October		0.0965
November		0.0965
December		0.0965
January		0.0965
February		0.0965
March		0.0965

Total Distributions from Net Investment Income		$1.1120


Yields	NBB

Market Yield*		7.23%

*	Market Yield is based on the Fund’s current annualized monthly distribution divided by the Fund’s current market price as of the end of the reporting period.

The Fund’s distribution policy, which may be changed by the Board, is to make regular monthly cash distributions to holders of its common shares (stated in terms of a fixed cents per common share dividend distribution rate which may be set from time to time). The Fund intends to distribute all or substantially all of its net investment income each year through its regular monthly distribution and to distribute realized capital gains at least annually. In addition, in any monthly period, to maintain its declared per common share distribution amount, the Fund may distribute more or less than its net investment income during the period. In the event the Fund distributes more than its net investment income during any yearly period, such distributions may also include realized gains and/or a return of capital. To the extent that a distribution includes a return of capital the NAV per share may erode. If a distribution includes anything other than net investment income, the Fund provides a notice of the best estimate of its distribution sources at the time of the distribution which may be viewed at www.nuveen.com/CEFdistributions. These estimates may not match the final tax characterization (for the full year’s distributions) contained in shareholders’ 1099-DIV forms after the end of the year.

NUVEEN CLOSED-END FUND DISTRIBUTION AMOUNTS

The Nuveen Closed-End Funds’ monthly and quarterly periodic distributions to shareholders are posted on www.nuveen.com and can be found on Nuveen’s enhanced closed-end fund resource page, which is at https://www.nuveen.com/resource-center- closed-end-funds, along with other Nuveen closed-end fund product updates. To ensure timely access to the latest information, shareholders may use a subscribe function, which can be activated at this web page (https://www.nuveen.com/subscriptions).

COMMON SHARE EQUITY SHELF PROGRAMS

During the current reporting period, the Fund was authorized by the Securities and Exchange Commission to issue additional common shares through an equity shelf program (Shelf Offering). Under these programs, the Fund, subject to market conditions, may raise additional capital from time to time in varying amounts and offering methods at a net price at or above the Fund’s NAV per common share. The maximum aggregate offering under these Shelf Offerings are as shown in the accompanying table.


	NBB

Maximum aggregate offering	$	120,480,111

During the current reporting period, the Fund did not sell any common shares through its shelf offering.

Refer to Notes to Financial Statements, for further details of Shelf Offerings and the Fund’s transactions.

COMMON SHARE REPURCHASES

The Fund’s Board of Trustees authorized an open-market share repurchase program, allowing the Fund to repurchase and retire an aggregate of up to approximately 10% of its outstanding common shares.

During the current reporting period, the Fund did not repurchase any of its outstanding common shares. As of March 31, 2025, (and since the inception of the Fund’s repurchase programs), the Fund has cumulatively repurchased and retired its outstanding common shares as shown in the accompanying table.


	NBB

Common shares cumulatively repurchased and retired		0
Common shares authorized for repurchase		2,935,000

About the Fund’s Benchmark

Bloomberg Taxable Municipal Long Bond Index: A rules-based index engineered for the long-term taxable municipal bond market. Bonds in the index have effective maturities of 10+ years. Index returns assume reinvestment of distributions, but do not reflect any applicable sales charges or management fees.

Fund Performance, Leverage and Holdings Summaries

The Fund Performance, Leverage and Holdings Summaries for the Fund are shown below within this section of the report.

Fund Performance

Performance data shown represents past performance and does not predict or guarantee future results. Current performance may be higher or lower than the data shown. Returns do not reflect the deduction of taxes that shareholders may have to pay on Fund distributions or upon the sale of Fund shares. Returns at NAV are net of Fund expenses, and assume reinvestment of distributions. Comparative index return information is provided for the Fund’s shares at NAV only. Indexes are not available for direct investment.

Total returns for a period of less than one year are not annualized (i.e. cumulative returns). Since inception returns are shown for share classes that have less than 10-years of performance. For performance, current to the most recent month-end visit Nuveen.com or call (800) 257-8787.

Impact of Leverage

One important factor impacting the returns of the Fund’s common shares relative to its comparative benchmarks was the Fund’s use of leverage through its issuance of reverse repurchase agreements and investments in inverse floating rate securities, which represent leveraged investments in underlying bonds. The Fund uses leverage because our research has shown that, over time, leveraging provides opportunities for additional income. The opportunity arises when short-term rates that the Fund pays on its leveraging instruments are lower than the interest the Fund earns on its portfolio of long-term bonds that it has bought with the proceeds of that leverage.

However, use of leverage can expose Fund common shares to additional price volatility. When the Fund uses leverage, the Fund’s common shares will experience a greater increase in their net asset value if the securities acquired through the use of leverage increase in value, but will also experience a correspondingly larger decline in their net asset value if the securities acquired through leverage decline in value. All this will make the shares’ total return performance more variable over time.

In addition, common share income in levered funds will typically decrease in comparison to unlevered funds when short-term interest rates increase and increase when short-term interest rates decrease. In recent quarters, fund leverage expenses have generally tracked the overall movement of short-term interest rates. While fund leverage expenses are higher than their prior year lows, leverage nevertheless continues to provide the opportunity for incremental common share income, particularly over longer-term periods.

Leverage Ratios

The Fund’s Effective Leverage and Regulatory Leverage Ratios are set forth below. “Effective Leverage” is a Fund’s effective economic leverage, and includes both regulatory leverage and the leverage effects of certain derivative and other investments in a Fund’s portfolio that increase the Fund’s investment exposure. Currently, the leverage effects of Tender Option Bond (TOB) inverse floater holdings are included in effective leverage values, in addition to any regulatory leverage. “Regulatory Leverage” consists of preferred shares or borrowings of a Fund. Regulatory Leverage is a part of a Fund’s capital structure. Regulatory leverage is subject to asset coverage limits set forth in the Investment Company Act of 1940. A Fund, however, may from time to time borrow for temporary purposes, typically on a transient basis in connection with its day-to-day operations, primarily in connection with the need to settle portfolio trades. Such temporary borrowings are excluded from the calculation of a Fund’s Effective Leverage and Regulatory Leverage ratios.

Holding Summaries

The Holdings Summaries data relates to the securities held in the Fund’s portfolio of investments as of the end of this reporting period. It should not be construed as a measure of performance for the Fund itself. Holdings are subject to change. Refer to the Fund’s Portfolio of Investments for individual security information.

For financial reporting purposes, the ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s, Moody’s Investors Service, Inc. or Fitch, Inc. This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below investment grade ratings. Holdings designated N/R are not rated by these national rating agencies.


NBB		Nuveen Taxable Municipal Income Fund
NBB		Fund Performance, Leverage and Holdings Summaries March 31, 2025

Performance*

Total Returns as of
March 31, 2025

Average Annual

Inception

Date

1-Year

5-Year

10-Year

NBB at Common Share NAV

4/27/10

Amendment: SEC Form N-CSR/A filed by Nuveen Taxable Municipal Income Fund