Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2 below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (CFR 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (CFR 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

EXPLANATORY NOTE

On May 31, 2023, Putnam Municipal Opportunities Trust (the “Fund”) filed a Current Report on Form 8-K (the “Original 8-K”) to disclose, among other things, that Franklin Resources, Inc. (“Franklin Resources”) and Great-West Lifeco Inc., the parent company of Putnam U.S. Holdings I, LLC (“Putnam Holdings”), announced that they entered into a definitive agreement for a subsidiary of Franklin Resources to acquire Putnam Holdings in a stock and cash transaction and that as part of this transaction, Putnam Investment Management, LLC (“Putnam Management”), a wholly owned subsidiary of Putnam Holdings and investment manager to the Putnam family of funds (the “Putnam Funds”), including Putnam Municipal Opportunities Trust, would become an indirect wholly owned subsidiary of Franklin Resources. This Amendment No. 1 to the Original 8-K is being filed solely to add iXBRL tagging to the Original 8-K. No other changes are being made to the Original 8-K.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.