MIO Pioneer Municipal High Income Opportunities Fund Inc

Notes to Financial Statements | 10/31/22

(unaudited)

1. Organization and Significant Accounting Policies

Pioneer Municipal High Income Opportunities Fund, Inc. (the “Fund”) is a newly organized, diversified, closed-end management investment company. The Fund is organized as a Maryland corporation. Prior to commencing operations on August 6, 2021, the Fund had no operations other than matters related to its organization and registration under the Investment Company Act of 1940, as amended (the “1940 Act”). The Fund issued 5,000 common shares on June 15, 2021, 15,000,000 common shares on August 5, 2021*, 1,000,000 shares on September 14, 2021, and 880,273 shares on September 21, 2021. The Fund’s primary investment objective is to provide holders of the Fund’s common stock (“Common Shares”) with a high level of current income exempt from regular federal income tax. As a secondary investment objective, the Fund may seek capital appreciation to the extent consistent with its primary investment objective. Distributions from sources other than interest income from the Fund’s portfolio of municipal securities, including capital gain distributions, are not exempt from regular federal income tax. There can be no assurance that the Fund will achieve its investment objectives.

Amundi Asset Management US, Inc., an indirect, wholly owned subsidiary of Amundi and Amundi’s wholly owned subsidiary, Amundi USA, Inc., serves as the Fund’s investment adviser (the “Adviser”).

In March 2020, FASB issued an Accounting Standard Update, ASU 2020-04, Reference Rate Reform (Topic 848) — Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”), which provides optional, temporary relief with respect to the financial reporting of contracts subject to certain types of modifications due to the planned discontinuation of the London Interbank Offered Rate (“LIBOR”) and other LIBOR-based reference rates at the end of 2021. The temporary relief provided by ASU 2020-04 is effective for certain reference rate-related contract modifications that occur during the period from March 12, 2020 through December 31, 2023. Management is evaluating the impact of ASU 2020-04 on the Fund's investments, derivatives, debt and other contracts, if applicable, that will undergo reference rate-related modifications as a result of the reference rate reform.

Effective August 19, 2022, the Fund is required to comply with Rule 18f-4 under the 1940 Act, which governs the use of derivatives by registered investment companies. Rule 18f-4 permits funds to enter into derivatives

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transactions (as defined in Rule 18f-4) and certain other transactions notwithstanding the restrictions on the issuance of “senior securities” under Section 18 of the 1940 Act. Rule 18f-4 requires a fund to establish and maintain a comprehensive derivatives risk management program, appoint a derivatives risk manager and comply with a relative or absolute limit on fund leverage risk calculated based on value-at-risk (“VaR”), unless the fund uses derivatives in only a limited manner.

The Fund is an investment company and follows investment company accounting and reporting guidance under U.S. Generally Accepted Accounting Principles (“U.S. GAAP”). U.S. GAAP requires the management of the Fund to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of income, expenses and gain or loss on investments during the reporting period. Actual results could differ from those estimates.

The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements:

The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (“NYSE”) is open, as of the close of regular trading on the NYSE.

Fixed-income securities are valued by using prices supplied by independent pricing services, which consider such factors as market prices, market events, quotations from one or more brokers, Treasury spreads, yields, maturities and ratings, or may use a pricing matrix or other fair value methods or techniques to provide an estimated value of the security or instrument. A pricing matrix is a means of valuing a debt security on the basis of current market prices for other debt securities, historical trading patterns in the market for fixed-income securities and/or other factors. Non-U.S. debt securities that are listed on an exchange will be valued at the bid price obtained from an independent third party pricing service. When independent third party pricing services are unable to supply prices, or when prices or market quotations are considered to be unreliable, the value of that security may be determined using quotations from one or more broker-dealers.

Securities for which independent pricing services or broker-dealers are unable to supply prices or for which market prices and/or quotations are not readily available or are considered to be unreliable are valued by a fair valuation team comprised of certain personnel of the Adviser. Effective September 8, 2022, the Adviser is designated as the valuation designee for

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the Fund pursuant to Rule 2a-5 under the 1940 Act. The Adviser’s fair valuation team is responsible for monitoring developments that may impact fair valued securities.

Inputs used when applying fair value methods to value a security may include credit ratings, the financial condition of the company, current market conditions and comparable securities. The Adviser may use fair value methods if it is determined that a significant event has occurred after the close of the exchange or market on which the security trades and prior to the determination of the Fund’s net asset value. Examples of a significant event might include political or economic news, corporate restructurings, natural disasters, terrorist activity or trading halts. Thus, the valuation of the Fund’s securities may differ significantly from exchange prices, and such differences could be material.

Interest income, including interest on income-bearing cash accounts, is recorded on the accrual basis. Dividend and interest income are reported net of unrecoverable foreign taxes withheld at the applicable country rates and net of income accrued on defaulted securities.

Discounts and premiums on purchase prices of debt securities are accreted or amortized, respectively, daily, into interest income on an effective yield to maturity basis with a corresponding increase or decrease in the cost basis of the security. Premiums and discounts related to certain mortgage-backed securities are amortized or accreted in proportion to the monthly paydowns.

Interest and dividend income payable by delivery of additional shares is reclassified as PIK (payment-in-kind) income upon receipt and is included in interest and dividend income, respectively.

Security transactions are recorded as of trade date. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes.

It is the Fund's policy to comply with the requirements of the Internal Revenue Code applicable to regulated investment companies and to distribute all of its net taxable income and net realized capital gains, if any, to its shareowners. Therefore, no provision for federal income taxes is required. As of April 30, 2022, the Fund did not accrue any interest or penalties with respect to uncertain tax positions, which, if applicable,

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would be recorded as an income tax expense on the Statement of Operations. Tax returns filed within the prior three years remain subject to examination by federal and state tax authorities.

The amount and character of income and capital gain distributions to shareowners are determined in accordance with federal income tax rules, which may differ from U.S. GAAP. Distributions in excess of net investment income or net realized gains are temporary over distributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences.

The tax character of current year distributions payable will be determined at the end of the current taxable year. The tax character of distributions paid during the year ended April 30, 2022 was as follows:

The following shows the components of distributable earnings (losses) on a federal income tax basis at April 30, 2022:

The differences between book-basis and tax-basis net unrealized depreciation are attributable to the tax deferral of losses on wash sales.

All shareowners whose shares are registered in their own names automatically participate in the Automatic Dividend Reinvestment Plan (the “Plan”), under which participants receive all dividends and capital gain distributions (collectively, dividends) in full and fractional shares of the Fund in lieu of cash. Shareowners may elect not to participate in the Plan. Shareowners not participating in the Plan receive all dividends and capital gain distributions in cash. Participation in the Plan is completely voluntary and may be terminated or resumed at any time without penalty

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by notifying American Stock Transfer & Trust Company, the agent for shareowners in administering the Plan (the “Plan Agent”), in writing prior to any dividend record date; otherwise such termination or resumption will be effective with respect to any subsequently declared dividend or other distribution.

If a shareowner’s shares are held in the name of a brokerage firm, bank or other nominee, the shareowner can ask the firm or nominee to participate in the Plan on the shareowner’s behalf. If the firm or nominee does not offer the Plan, dividends will be paid in cash to the shareowner of record. A firm or nominee may reinvest a shareowner’s cash dividends in shares of the Fund on terms that differ from the terms of the Plan.

Whenever the Fund declares a dividend on shares payable in cash, participants in the Plan will receive the equivalent in shares acquired by the Plan Agent either (i) through receipt of additional unissued but authorized shares from the Fund or (ii) by purchase of outstanding shares on the New York Stock Exchange or elsewhere. If, on the payment date for any dividend, the net asset value per share is equal to or less than the market price per share plus estimated brokerage trading fees (market premium), the Plan Agent will invest the dividend amount in newly issued shares. The number of newly issued shares to be credited o each account will be determined by dividing the dollar amount of the dividend by the net asset value per share on the date the shares are issued, provided that the maximum discount from the then current market price per share on the date of issuance does not exceed 5%. If, on the payment date for any dividend, the net asset value per share is greater than the market value (market discount), the Plan Agent will invest the dividend amount in shares acquired in open-market purchases. There are no brokerage charges with respect to newly issued shares. However, each participant will pay a pro rata share of brokerage trading fees incurred with respect to the Plan Agent’s open-market purchases. Participating in the Plan does not relieve shareowners from any federal, state or local taxes which may be due on dividends paid in any taxable year. Shareowners holding Plan shares in a brokerage account may be able to transfer the shares to another broker and continue to participate in the Plan.

The value of securities held by the Fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political or regulatory conditions, recessions, the spread of infectious illness or other public health issues, inflation, changes in interest rates, armed conflict including Russia's military invasion of Ukraine, sanctions against Russia, other nations or individuals

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or companies and possible countermeasures, lack of liquidity in the bond markets or adverse investor sentiment. In the past several years, financial markets have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. These conditions may continue, recur, worsen or spread. In recent years, interest rates and credit spreads in the U.S. have been at historic lows. The U.S. Federal Reserve has raised certain interest rates, and interest rates may continue to go up. A general rise in interest rates could adversely affect the price and liquidity of fixed-income securities. Rates of inflation have recently risen. The value of assets or income from an investment may be worth less in the future as inflation decreases the value of money. As inflation increases, the real value of the Fund’s assets can decline as can the value of the Fund’s distributions.

The global pandemic of the novel coronavirus respiratory disease designated COVID-19 has resulted in major disruption to economies and markets around the world, including the United States. Global financial markets have experienced extreme volatility and severe losses, and trading in many instruments has been disrupted. Liquidity for many instruments has been greatly reduced for periods of time. Some sectors of the economy and individual issuers have experienced particularly large losses. These circumstances may continue to affect adversely the value and liquidity of the Fund’s investments. Following Russia’s invasion of Ukraine, Russian securities have lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future geopolitical or other events or conditions.

Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time.

At times, the Fund’s investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors.

Russia launched a large-scale invasion of Ukraine on February 24, 2022. In response to the military action by Russia, various countries, including the U.S., the United Kingdom, and European Union issued broad-ranging economic sanctions against Russia and Belarus and certain companies and individuals. Since then, Russian securities have lost all, or nearly all, their market value, and many other issuers, securities and markets have been

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adversely affected. The United States and other countries may impose sanctions on other countries, companies and individuals in light of Russia’s military invasion. The extent and duration of the military action or future escalation of such hostilities, the extent and impact of existing and future sanctions, market disruptions and volatility, and the result of any diplomatic negotiations cannot be predicted. These and any related events could have a significant impact on the value and liquidity of certain Fund investments, on Fund performance and the value of an investment in the Fund, particularly with respect to securities and commodities, such as oil, natural gas and food commodities, as well as other sectors with exposure to Russian issuers or issuers in other countries affected by the invasion, and are likely to have collateral impacts on market sectors globally.

Under normal circumstances, the Fund will invest substantially all of its assets in municipal securities. The municipal bond market can be susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. Municipal issuers may be adversely affected by rising health care costs, increasing unfunded pension liabilities, and by the phasing out of federal programs providing financial support. Unfavorable conditions and developments relating to projects financed with municipal securities can result in lower revenues to issuers of municipal securities, potentially resulting in defaults. Issuers often depend on revenues from these projects to make principal and interest payments. The value of municipal securities can also be adversely affected by changes in the financial condition of one or more individual municipal issuers or insurers of municipal issuers, regulatory and political developments, tax law changes or other legislative actions, and by uncertainties and public perceptions concerning these and other factors. Municipal securities may be more susceptible to down-grades or defaults during recessions or similar periods of economic stress. Financial difficulties of municipal issuers may continue or get worse, particularly in the event of political, economic or market turmoil or a recession. To the extent the Fund invests significantly in a single state (including New York and California), city, territory (including Puerto Rico), or region, or in securities the payments on which are dependent upon a single project or source of revenues, or that relate to a sector or industry, including tobacco settlement bond revenues, industrial development revenues, health care facilities, education, transportation, special revenues and pollution control, the Fund will be more susceptible to associated risks and developments.

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The Fund invests primarily in below investment grade (high yield) municipal securities. Debt securities, loans rated below investment grade are commonly referred to as “junk bonds” and are considered speculative with respect to the issuer's capacity to pay interest and repay principal. These securities involve greater risk of loss, are subject to greater price volatility, and may be less liquid and more difficult to value, especially during periods of economic uncertainty or change, than higher rated debt securities.

With the increased use of technologies such as the Internet to conduct business, the Fund is susceptible to operational, information security and related risks. While the Fund’s Adviser has established business continuity plans in the event of, and risk management systems to prevent, limit or mitigate, such cyber-attacks, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified. Furthermore, the Fund cannot control the cybersecurity plans and systems put in place by service providers to the Fund such as the Fund’s custodian and accounting agent, and the Fund's transfer agent. In addition, many beneficial owners of Fund shares hold them through accounts at broker-dealers, retirement platforms and other financial market participants over which neither the Fund nor the Adviser exercises control. Each of these may in turn rely on service providers to them, which are also subject to the risk of cyber-attacks. Cybersecurity failures or breaches at the Adviser or the Fund’s service providers or intermediaries have the ability to cause disruptions and impact business operations, potentially resulting in financial losses, interference with the Fund’s ability to calculate its net asset value, impediments to trading, the inability of Fund shareowners to effect share purchases or sales or receive distributions, loss of or unauthorized access to private shareowner information and violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, or additional compliance costs. Such costs and losses may not be covered under any insurance. In addition, maintaining vigilance against cyber-attacks may involve substantial costs over time, and system enhancements may themselves be subject to cyber-attacks.

Information on financial transactions which have been settled through the receipt or disbursement of cash is presented in the Statement of Cash Flows. Cash as presented in the Fund's Statement of Assets and Liabilities includes cash on hand at the Fund's custodian bank and does not include any short-term investments. For the six months ended October 31, 2022, the Fund had no restricted cash presented on the Statement of Assets and Liabilities.

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2. Management Agreement

The Adviser manages the Fund’s portfolio. Management fees payable under the Fund’s Investment Management Agreement with the Adviser are calculated daily and paid monthly at the annual rate of 0.80% of the Fund’s average daily managed assets. “Managed assets” means (a) the total assets of the Fund, including any form of investment leverage, minus (b) all accrued liabilities incurred in the normal course of operations, which shall not include any liabilities or obligations attributable to investment leverage obtained through (i) indebtedness of any type (including, without limitation, borrowing through a credit facility or the issuance of debt securities), (ii) the issuance of preferred stock or other similar preference securities, and/or (iii) any other means. For the six months ended October 31, 2022, the effective management fee (excluding waivers and/or assumption of expenses) was 0.80% (annualized) of the Fund’s average daily managed assets, which was equivalent to 1.19% (annualized) of the Fund’s average daily net assets.

During the six-months ended October 31, 2022, the Adviser voluntarily waived a portion of the management fees. There can be no assurance that the Adviser will extend this voluntary waiver in the future. Fees waived and expenses reimbursed during the six-months ended October 31, 2022 are reflected in the Statement of Operations.

In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting and insurance premiums, are paid by the Fund as administrative reimbursements. Included in “Due to affiliates” reflected on the Statement of Assets and Liabilities is $39,178 in management fees, administrative costs and certain other reimbursements payable to the Adviser at October 31, 2022.

3. Compensation of Directors and Officers

The Fund pays an annual fee to its Directors. The Adviser reimburses the Fund for fees paid to the Interested Directors. The Fund does not pay any salary or other compensation to its officers. For the six months ended October 31, 2022, the Fund paid $7,388 in Directors’ compensation, which is reflected on the Statement of Operations as Directors’ fees. At October 31, 2022, the Fund had a payable for Directors’ fees on its Statement of Assets and Liabilities of $1,098.

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4. Transfer Agent

American Stock Transfer & Trust Company (“AST”) serves as the transfer agent with respect to the Fund’s common shares. The Fund pays AST an annual fee as is agreed to from time to time by the Fund and AST for providing such services

In addition, the Fund reimbursed the transfer agent for out-of-pocket expenses incurred by the transfer agent related to shareowner communications activities such as proxy and statement mailings and outgoing phone calls.

5. Fund Shares

There are 1,000,000,000 shares of common stock of the Fund (“common shares”), $0.001 par value per share authorized. Transactions in common shares for the six months ended October 31, 2022 and period ended April 30, 2022 were as follows:

6. Credit Agreement

The Fund has entered into a credit facility (the "Credit Agreement") with The Bank of New York Mellon. There is a $150,000,000 borrowing limit under the Credit Agreement. The outstanding loans under the Credit Agreement bear interest at a rate equal to the Overnight Bank Funding Rate plus 0.95% per annum.

At October 31, 2022, the Fund had a borrowing outstanding under the credit agreement totaling $92,000,000. The interest rate charged at October 31, 2022 was 3.97%. During the period ended October 31, 2022, the average daily balance under the Credit Agreement was $108,368,859 at an average interest rate of 2.75%. Interest expense of $1,524,895 in connection with the credit agreement is included on the Statement of Operations.

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Borrowings under the Credit Agreement are subject to certain limitations, including (a) that the outstanding amount of the loans under the Credit Agreement cannot exceed the lesser of (i) $150,000,000 and (ii) the sum of the collateral value of all “Eligible Securities” (which consist of nondistressed U.S. municipal bonds, with certain concentration limits) over which The Bank of New York Mellon has a first lien, divided by the “Margin” (which ranges from 120% to 200% depending on the rating of the Eligible Security) and (b) any limitations imposed by applicable law, including the Investment Company Act of 1940, as amended.

The Credit Agreement renews on a daily basis in perpetuity. The Bank of New York Mellon may, at any time, deliver to the Fund a termination notice, which becomes effective 180 days after its receipt by the Fund.

7. Subsequent Events

A monthly distribution was declared on November 4, 2022 of $0.0630 per common share payable November 30, 2022, to common shareowners of record on November 16, 2022.

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Additional Information (unaudited)

Notice is hereby given in accordance with Section 23(c) of the Investment Company Act of 1940 that the Fund may purchase, from time to time, its shares in the open market.