X0202 SCHEDULE 13D/A 0000070858 XXXXXXXX LIVE 9 ADJUSTABLE RATE MUNIFUND TERM PREFERRED SHARES 04/27/2026 false 0001266585 670682111 670682889 NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND

333 W WACKER DRIVE CHICAGO IL 60606

Bank of America Corporation 980-825-9256 Bank of America Corporate Center 100 N. Tryon Street Charlotte NC 28255 0000070858 N BANK OF AMERICA CORP /DE/ b WC Y DE 0.00 1870.00 0.00 1870.00 1870.00 N 23.2 HC 0001565450 N Banc of America Preferred Funding Corp b WC N DE 0.00 1870.00 0.00 1870.00 1870.00 N 23.2 CO ADJUSTABLE RATE MUNIFUND TERM PREFERRED SHARES NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND 333 W WACKER DRIVE CHICAGO IL 60606 This Amendment No. 9 (this "Amendment") amends, as set forth below, the statement on Schedule 13D, dated December 21, 2012 and filed with the SEC on December 28, 2012, (as amended to the date hereof, the "Original Schedule 13D"), for Bank of America Corporation ("BAC") and Banc of America Preferred Funding Corporation ("BAPFC") (collectively, the "Reporting Persons") with respect to the Adjustable Rate Muni Fund Term Preferred Shares ("AMTP Shares") of Nuveen Municipal High Income Opportunity Fund (the "Issuer"). This amendment is being filed to report a change in the Reporting Persons' ownership percentage of the Issuer's class of preferred shares as a result of the reorganization of Nuveen New Jersey Quality Municipal Income Fund and Nuveen Pennsylvania Quality Municipal Income Fund with and into the Issuer (the "reorganization") and in connection with such reorganization the Issuer issued new Series 1 Variable Rate Demand Preferred Shares on April 27, 2026 Item 2(c) of the Original Schedule 13D is hereby amended by deleting Schedule I referenced therein and replacing it with Schedule I included with this Amendment. Item 2(d) of the Original Schedule 13D is hereby amended by deleting Schedule II referenced therein and replacing it with Schedule II included with this Amendment. Item 7 of the Original Schedule 13D is hereby amended by deleting Exhibit 99.1 and Exhibit 99.2 thereto and the insertion of the following exhibits: Exhibit Description of Exhibit 99.1 Joint Filing Agreement 99.2 Power of Attorney 99.7 Schedule I 99.8 Schedule II BANK OF AMERICA CORP /DE/ /s/ Andres Ortiz 04/29/2026 Banc of America Preferred Funding Corp /s/ Andres Ortiz 04/29/2026