Pioneer Municipal High Income Opportunities Fund, Inc.

Symbol
MIO on NYSE
Entity
Company
Business address
60 State Street, 5 Th Floor, 02109 Boston, MA
Phone
617-742-7825
State of incorporation
MD
Fiscal year end
April 30
All SEC filings
View on sec.gov
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Pioneer Municipal High Income Opportunities Fund, Inc. has filed 170 SEC EDGAR filings since 5/26/2021

Latest Filings

Form type Document Filing Description Filing date Reporting date File number(s)
4 Open Document Open Filing PRIMARY DOCUMENT Sep 2, 2025 Aug 27, 2025
SCHEDULE 13D/A Open Document Open Filing Sep 2, 2025 005-93825
N-PX Open Document Open Filing Aug 27, 2025 Jun 30, 2025 811-23699
25-NSE Open Document Open Filing Aug 27, 2025 001-40705
SCHEDULE 13G/A Open Document Open Filing Aug 14, 2025 005-93825
N-CEN Open Document Open Filing Jul 14, 2025 Apr 30, 2025 811-23699
N-CSR Open Document | Data Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jul 9, 2025 Apr 30, 2025 811-23699
DEFA14A Open Document Open Filing ADDITIONAL DEFINITIVE PROXY MATERIALS Jul 9, 2025 811-23699
NPORT-P Open Document Open Filing Jun 27, 2025 Apr 30, 2025 811-23699
DEF 14A Open Document Open Filing DEF 14A Jun 10, 2025 Jul 17, 2025 811-23699
CORRESP Open Document Open Filing Jun 3, 2025
PRE 14A Open Document Open Filing CEF FUNDS May 20, 2025 Jul 17, 2025 811-23699
8-K Open Document Open Filing 8-K May 20, 2025 May 20, 2025 811-23699
8-K Open Document Open Filing 8-K May 9, 2025 May 7, 2025 811-23699
8-K Open Document Open Filing 8-K May 8, 2025 May 7, 2025 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT May 8, 2025 May 7, 2025
4 Open Document Open Filing PRIMARY DOCUMENT May 1, 2025 Apr 29, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Apr 24, 2025 Apr 22, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Apr 22, 2025 Apr 21, 2025
40-17G Open Document Open Filing VP IV AND VVIF II FIDELITY BOND 2025 Apr 14, 2025 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Apr 14, 2025 Apr 11, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Apr 10, 2025 Apr 8, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Apr 8, 2025 Apr 7, 2025
3 Open Document Open Filing PRIMARY DOCUMENT Apr 4, 2025 Apr 1, 2025
8-K Open Document Open Filing 8-K Apr 2, 2025 Apr 1, 2025 811-23699
DEFA14A Open Document Open Filing DEFINITIVE ADDITIONAL MATERIALS Mar 26, 2025 811-23699
8-K Open Document Open Filing 8-K Mar 25, 2025 Mar 25, 2025 811-23699
NPORT-P Open Document Open Filing Mar 25, 2025 Jan 31, 2025 811-23699
DFAN14A Open Document Open Filing Feb 24, 2025 811-23699
SCHEDULE 13G Open Document Open Filing Feb 14, 2025 005-93825
DEFC14A Open Document Open Filing MIO Feb 11, 2025 811-23699
CORRESP Open Document Open Filing Feb 10, 2025
DEFC14A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Feb 10, 2025 811-23699
SCHEDULE 13D/A Open Document Open Filing Feb 4, 2025 005-93825
4 Open Document Open Filing PRIMARY DOCUMENT Feb 3, 2025 Jan 31, 2025
PRRN14A Open Document Open Filing Jan 31, 2025 811-23699
PREC14A Open Document Open Filing MIO Jan 29, 2025 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Jan 29, 2025 Jan 27, 2025
SCHEDULE 13D/A Open Document Open Filing Jan 28, 2025 005-93825
4 Open Document Open Filing PRIMARY DOCUMENT Jan 27, 2025 Jan 23, 2025
PREC14A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jan 24, 2025 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Jan 23, 2025 Jan 21, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Jan 21, 2025 Jan 16, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Jan 14, 2025 Jan 10, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Jan 10, 2025 Jan 8, 2025
4 Open Document Open Filing PRIMARY DOCUMENT Jan 6, 2025 Jan 2, 2025
N-CSRS Open Document | Data Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC Jan 3, 2025 Oct 31, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Dec 31, 2024 Dec 27, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Dec 27, 2024 Dec 23, 2024
SCHEDULE 13D/A Open Document | Data Open Filing Dec 23, 2024 005-93825
4 Open Document Open Filing PRIMARY DOCUMENT Dec 23, 2024 Dec 19, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Dec 19, 2024 Dec 17, 2024
NPORT-P Open Document Open Filing Dec 19, 2024 Oct 31, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Dec 16, 2024 Dec 12, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Dec 12, 2024 Dec 10, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 29, 2024 Nov 26, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 26, 2024 Nov 25, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 25, 2024 Nov 21, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 21, 2024 Nov 19, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 18, 2024 Nov 14, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 14, 2024 Nov 12, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 12, 2024 Nov 11, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 5, 2024 Nov 4, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Nov 4, 2024 Oct 31, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Oct 31, 2024 Oct 29, 2024
DEFA14A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Oct 22, 2024 811-23699
DEFA14A Open Document Open Filing DEFINITIVE ADDITIONAL MATERIALS Sep 27, 2024 811-23699
NPORT-P Open Document Open Filing Sep 23, 2024 Jul 31, 2024 811-23699
40-17G Open Document Open Filing PIONEER FAMILY OF MUTUAL FUNDS Sep 10, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Aug 29, 2024 Aug 28, 2024
N-PX Open Document Open Filing Aug 28, 2024 Jun 30, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Aug 27, 2024 Aug 23, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Aug 23, 2024 Aug 22, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Aug 22, 2024 Aug 21, 2024
DEF 14A Open Document Open Filing MHI MAV MIIO Aug 22, 2024 Oct 3, 2024 811-23699
SC 13D/A Open Document Open Filing FORM SC 13D/A Aug 21, 2024 005-93825
DEFC14A Open Document Open Filing MIO Aug 19, 2024 811-23699
CORRESP Open Document Open Filing Aug 15, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Aug 15, 2024 Aug 13, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Aug 13, 2024 Aug 12, 2024
PREC14A Open Document Open Filing MIO Aug 9, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Aug 8, 2024 Aug 7, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Aug 6, 2024 Aug 5, 2024
8-K Open Document Open Filing 8-K Jul 19, 2024 Jul 15, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT Jul 15, 2024 Jul 11, 2024
N-CEN Open Document Open Filing Jul 12, 2024 Apr 30, 2024 811-23699
N-CSR Open Document | Data Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jul 8, 2024 Apr 30, 2024 811-23699
NPORT-P Open Document Open Filing Jun 27, 2024 Apr 30, 2024 811-23699
4 Open Document Open Filing PRIMARY DOCUMENT May 31, 2024 May 28, 2024
4 Open Document Open Filing PRIMARY DOCUMENT May 17, 2024 May 15, 2024
SC 13D/A Open Document Open Filing FORM SC 13D/A Apr 1, 2024 005-93825
NPORT-P Open Document Open Filing Mar 21, 2024 Jan 31, 2024 811-23699
3 Open Document Open Filing PRIMARY DOCUMENT Mar 21, 2024 Feb 28, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Mar 20, 2024 Mar 19, 2024
CORRESP Open Document Open Filing Mar 19, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Mar 11, 2024 Mar 7, 2024
4 Open Document Open Filing PRIMARY DOCUMENT Mar 6, 2024 Mar 6, 2024
3 Open Document Open Filing PRIMARY DOCUMENT Mar 6, 2024 Feb 28, 2024
3 Open Document Open Filing PRIMARY DOCUMENT Mar 6, 2024 Mar 5, 2024
3 Open Document Open Filing PRIMARY DOCUMENT Jan 30, 2024 Jan 22, 2024
SC 13D Open Document Open Filing FORM SC 13D Jan 5, 2024 005-93825
N-CSRS Open Document | Data Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC Jan 3, 2024 Oct 31, 2023 811-23699
NPORT-P Open Document Open Filing Dec 20, 2023 Oct 31, 2023 811-23699
N-CEN/A Open Document Open Filing Oct 25, 2023 Apr 30, 2022 811-23699
NPORT-P Open Document Open Filing Sep 26, 2023 Jul 31, 2023 811-23699
40-17G Open Document Open Filing PIONEER FAMILY OF MUTUAL FUNDS Sep 14, 2023 811-23699
3 Open Document Open Filing PRIMARY DOCUMENT Sep 5, 2023 Sep 1, 2023
N-PX Open Document Open Filing FORM N-PX Aug 28, 2023 Jun 30, 2023 811-23699
DEFA14A Open Document Open Filing DEFINITIVE ADDITIONAL MATERIALS Aug 18, 2023 811-23699
DEFA14A Open Document Open Filing DEFINITIVE ADDITIONAL MATERIALS Aug 11, 2023 811-23699
DEFA14A Open Document Open Filing DEFINITIVE ADDITIONAL MATERIALS Aug 9, 2023 811-23699
DEF 14A Open Document Open Filing DEFINITIVE PROXY FILING Jul 26, 2023 Sep 12, 2023 811-23699
N-CEN Open Document Open Filing Jul 13, 2023 Apr 30, 2023 811-23699
N-CSR Open Document | Data Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC Jul 7, 2023 Apr 30, 2023 811-23699
NPORT-P Open Document Open Filing Jun 22, 2023 Apr 28, 2023 811-23699
NPORT-P Open Document Open Filing Mar 22, 2023 Jan 31, 2023 811-23699
SC 13G/A Open Document Open Filing FORM SC 13G/A Feb 14, 2023 005-93825
SC 13G Open Document Open Filing Feb 13, 2023 005-93825
N-CSRS Open Document Open Filing PIONEER MUNICPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jan 4, 2023 Oct 31, 2022 811-23699
NPORT-P Open Document Open Filing Dec 21, 2022 Oct 31, 2022 811-23699
SC 13G Open Document Open Filing FORM SC 13G Nov 22, 2022 005-93825
NPORT-P Open Document Open Filing Sep 23, 2022 Jul 29, 2022 811-23699
40-17G Open Document Open Filing PIONEER FAMILY OF MUTUAL FUNDS Sep 15, 2022 811-23699
N-PX Open Document Open Filing N-PX Aug 29, 2022 Jun 30, 2022 811-23699
DEFA14A Open Document Open Filing DEFINITIVE ADDITIONAL MATERIALS Aug 22, 2022 811-23699
DEFA14A Open Document Open Filing PIONEER FUNDS Aug 12, 2022 811-23699
DEFA14A Open Document Open Filing PIONEER FUNDS Aug 12, 2022 811-23699
DEF 14A Open Document Open Filing DEFINITIVE PROXY FILING Jul 29, 2022 Sep 15, 2022 811-23699
N-CEN Open Document Open Filing Jul 12, 2022 Apr 30, 2022 811-23699
N-CSR Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jul 1, 2022 Apr 30, 2022 811-23699
NPORT-P Open Document Open Filing Jun 23, 2022 Apr 29, 2022 811-23699
NPORT-P Open Document Open Filing Mar 30, 2022 Jan 31, 2022 811-23699
N-CSRS Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jan 3, 2022 Oct 31, 2021 811-23699
NPORT-P Open Document Open Filing Dec 23, 2021 Oct 31, 2021 811-23699
40-17G Open Document Open Filing PIONEER FAMILY OF MUTUAL FUNDS Sep 27, 2021 811-23699
3 Open Document Open Filing PRIMARY DOCUMENT Sep 20, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 20, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 20, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 18, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 16, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 10, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 10, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 10, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 10, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 10, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
3 Open Document Open Filing PRIMARY DOCUMENT Aug 9, 2021 Aug 5, 2021
424B1 Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Aug 6, 2021 333-256506
EFFECT Open Document Open Filing Aug 5, 2021 333-256506
N-2/A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Aug 4, 2021 811-23699,333-256506
CORRESP Open Document Open Filing Aug 3, 2021
CORRESP Open Document Open Filing Aug 3, 2021
CERT Open Document Open Filing NYSE CERTIFICATION Aug 3, 2021 001-40705
8-A12B Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Aug 3, 2021 001-40705
N-2/A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jul 28, 2021 811-23699,333-256506
N-2/A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jul 26, 2021 811-23699,333-256506
CORRESP Open Document Open Filing Jul 23, 2021
N-2/A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. Jul 13, 2021 811-23699,333-256506
CORRESP Open Document Open Filing Jul 13, 2021
UPLOAD Open Document Open Filing Jul 1, 2021
N-2 Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. May 26, 2021 811-23699,333-256506
N-8A Open Document Open Filing PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. May 26, 2021 811-23699