UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 820, 2025

PIONEER FLOATING RATE FUND, INC.

(Registrant)

PIONEER DIVERSIFIED HIGH INCOME FUND, INC.

PIONEER HIGH INCOME FUND, INC.

PIONEER MUNICIPAL HIGH INCOME FUND, INC.

(Registrant)

PIONEER MUNICIPAL HIGH INCOME ADVANTAGE FUND, INC.

PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC.

(Co-Registrants)

(Exact name of registrant as specified in its charter)

Maryland	811-~~21654 (Pioneer Floating Rate Fund, Inc.) 811-22014 (Pioneer Diversified High Income Fund, Inc.) 811-21043 (Pioneer High Income Fund, Inc.) 811-~~21321 (Pioneer Municipal High Income Fund, Inc.) 811-21409 (Pioneer Municipal High Income Advantage Fund, Inc.) 811-23699 (Pioneer Municipal High Income Opportunities Fund, Inc.)	~~58-2683903 (Pioneer Floating Rate Fund, Inc.) 20-8779403 (Pioneer Diversified High Income Fund, Inc.) 02-0563892 (Pioneer High Income Fund, Inc.)~~ 03-0512430 (Pioneer Municipal High Income Fund, Inc.) 81-0634319 (Pioneer Municipal High Income Advantage Fund, Inc.) 87-0966308 (Pioneer Municipal High Income Opportunities Fund, Inc.)
(State or other jurisdictionof incorporation)	(Commission File Numbers)	(I.R.S. Employer Identification Nos.)
(State or other jurisdiction of incorporation)	(Commission File Numbers)	(I.R.S. Employer Identification Nos.)

60 State Street, Boston, MA		02109
(Address of principal executive offices)		(Zip Code)

60 State Street

Boston, MA

(Address of principal executive offices)

02109

(Zip Code)

617-742-7825

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

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:

☐	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))

~~☐ Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the~~ Securities ~~Act~~registered ofpursuant ~~1933~~to Section 12(~~§230.405 of this chapter~~b) ~~or Rule 12b-2~~ of the ~~Securities Exchange~~ Act: ~~of 1934 (§240.12b-2 of this chapter).~~


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock	MHI	New York Stock Exchange
Common Stock	MAV	New York Stock Exchange
Common Stock	MIO	New York Stock Exchange

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

Item 58.~~03.~~01 ~~Amendments~~Other ~~to Articles of Incorporation or Bylaws; Change in Fiscal Year~~Events.

OnEffective ~~May 6~~immediately, ~~2025,~~John ~~the~~(Jake) ~~Board~~Crosby ofvan ~~Directors~~Roden ofIII, ~~Pioneer~~Managing ~~Diversified~~Director ~~High~~and ~~Income~~Director ~~Fund,~~of ~~Inc.~~Municipals, US at Pioneer ~~Floating~~Investments ~~Rate~~is ~~Fund,~~responsible ~~Inc.,~~for ~~Pioneer~~the ~~High~~day-to-day ~~Income~~management ~~Fund,~~of ~~Inc.,~~ each of Pioneer Municipal High Income ~~Advantage~~ Fund, Inc., Pioneer Municipal High Income Advantage Fund, Inc. and Pioneer Municipal High Income Opportunities Fund, Inc. ~~(each,~~Pioneer aInvestments ~~“Fund”)~~is ~~amended~~an ~~the~~investment ~~Bylaws~~franchise of ~~the~~Victory ~~Fund~~Capital toManagement ~~remove Article II, Section 13~~Inc. ~~That~~ repealed Article II, Section 13 made the Fund subject to the Maryland Control Share Acquisition Act, which had the effect of limiting the exercise of voting rights in certain circumstances of a person who acquires more than a certain level of ownership of the Fund’s common stock.

~~Item~~Mr. van 9Roden, Managing Director and Director of Municipals, US, at Pioneer Investments, joined the Adviser following the integration of Amundi US into the Adviser and has served as portfolio manager of the fund since February 2024.01 ~~Financial~~Prior ~~Statements~~to joining Amundi US in 2024, Mr. van Roden was Managing Director and ~~Exhibits~~Senior Portfolio Manager at Macquarie Investment Management, which he joined in 2004.

~~(d)~~SIGNATURES ~~Exhibits:~~

Exhibit Number		Description
99.1		Amended and Restated Bylaws

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

~~SIGNATURES~~Date: May 20, 2025

~~Pursuant~~Pioneer toMunicipal ~~the~~High ~~requirements~~Income ofFund, ~~the~~Inc. ~~Securities~~Pioneer ~~Exchange~~Municipal ~~Act~~High ofIncome ~~1934~~Advantage Fund, ~~each~~Inc. ~~Registrant~~Pioneer ~~has~~Municipal ~~duly~~High ~~caused~~Income ~~this~~Opportunities ~~report~~Fund, toInc. be/s/ ~~signed~~Patricia onMcClain ~~its~~Name: ~~behalf~~Patricia ~~by the~~McClain ~~undersigned~~Title: ~~hereunto duly authorized.~~ Secretary

Date: May 8, 2025

Pioneer Floating Rate Fund, Inc. Pioneer High Income Fund, Inc. Pioneer Diversified High Income Fund, Inc. Pioneer Municipal High Income Fund, Inc. Pioneer Municipal High Income Advantage Fund, Inc. Pioneer Municipal High Income Opportunities Fund, Inc. /s/ Patricia McClain Name: Patricia McClain Title: Secretary

EXHIBIT INDEX

Exhibit Number		Description
99.1		Amended and Restated Bylaws

Filing Compare · PIONEER MUNICIPAL HIGH INCOME FUND, INC.