THORNBURG INVESTMENT TRUST SUPPLEMENT
Dated April 19, 2024

to the

THORNBURG FUNDS PROSPECTUS
applicable to Class A, C, C2, D and I shares
dated February 1, 2024, as supplemented March 13, 2024
(the “Retail Prospectus”)

Effective April 19, 2024, the following information is added to the end of the “Appendix A - Sales Charge Waivers Offered by Financial Intermediaries” section on page 222 of the Retail Prospectus:

J.P. Morgan Securities LLC

If you purchase or hold Fund shares through an applicable J.P. Morgan Securities LLC brokerage account, you will be eligible for the following sales charge waivers (front-end sales charge waivers and contingent deferred sales charge (“CDSC”), or back-end sales charge, waivers), share class conversion policy and discounts, which may differ from those disclosed elsewhere in the Fund’s prospectus or Statement of Additional Information (“SAI”).

Front-end sales charge waivers on Class A shares available at J.P. Morgan Securities LLC

•Shares exchanged from Class C (i.e., level-load) shares that are no longer subject to a CDSC and are exchanged into Class A shares of the same Fund pursuant to J.P. Morgan Securities LLC’s share class exchange policy.

•Qualified employer-sponsored defined contribution and defined benefit retirement plans, nonqualified deferred compensation plans, other employee benefit plans and trusts used to fund those plans.  For purposes of this provision, such plans do not include SEP IRAs, SIMPLE IRAs, SAR-SEPs or 501(c)(3) accounts.

•Shares of the Funds purchased through J.P. Morgan Securities LLC Self-Directed Investing accounts.

•Shares purchased through rights of reinstatement.

•Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same Fund (but not any other Fund within the Fund family).

•Shares purchased by employees and registered representatives of J.P. Morgan Securities LLC or its affiliates and their spouse or financial dependent as defined by J.P. Morgan Securities LLC.

Class C to Class A share conversion

•A shareholder in the Fund’s Class C shares will have their shares converted by J.P. Morgan Securities LLC to Class A shares (or the appropriate share class) of the same Fund if the shares are no longer subject to a CDSC and the conversion is consistent with J.P. Morgan Securities LLC’s policies and procedures.

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CDSC waivers on Class A and C shares available at J.P. Morgan Securities LLC

•Shares sold upon the death or disability of the shareholder.

•Shares sold as part of a systematic withdrawal plan as described in the Fund’s prospectus.

•Shares purchased in connection with a return of excess contributions from an IRA account.

•Shares sold as part of a required minimum distribution for IRA and retirement accounts pursuant to the Internal Revenue Code.

•Shares acquired through a right of reinstatement.

Front-end load discounts available at J.P. Morgan Securities LLC: breakpoints, rights of accumulation & letters of intent

•Breakpoints as described in the prospectus.

•Rights of Accumulation (“ROA”) which entitle shareholders to breakpoint discounts as described in the Fund’s prospectus will be automatically calculated based on the aggregated holding of Fund family assets held by accounts within the purchaser’s household at J.P. Morgan Securities LLC. Eligible Fund family assets not held at J.P. Morgan Securities LLC (including 529 program holdings, where applicable) may be included in the ROA calculation only if the shareholder notifies their financial advisor about such assets.

•Letters of Intent (“LOI”) which allow for breakpoint discounts based on anticipated purchases within the Fund family, through J.P. Morgan Securities LLC, over a 13-month period of time (if applicable).

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PLEASE KEEP THIS SUPPLEMENT FOR FUTURE REFERENCE

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