BlackRock New York Municipal Opportunities Fund

BLACKROCK MULTI-STATE MUNICIPAL SERIES TRUST

(the “Fund”)

Supplement dated October 28, 2026 to

the Summary Prospectuses, Prospectuses and Statement of Additional Information (“SAI”)

of the Fund, each dated October 28, 2026

This Supplement contains information that is identical to certain information provided in the supplement dated September 29, 2026 to the prior summary prospectuses, prospectuses and statement of additional information of the Fund, each dated October 28, 2025, as supplemented to date.

The Board of Trustees (the “Board”) of BlackRock Multi-State Municipal Series Trust (the “Trust”) has approved a proposal, pursuant to which the following changes will be effective on or about April 6, 2027:

•

The Fund will convert to a unitary administration fee structure by entering into a new administration agreement (the “Administration Agreement”) with the Fund’s administrator, BlackRock Advisors, LLC (“BlackRock”), pursuant to which BlackRock will provide administration services and pay for all expenses incurred by the Fund, excluding certain expenses described in the Administration Agreement. Under the Administration Agreement, the Trust, on behalf of the Fund, will pay BlackRock the following fee with respect to each share class: 0.14% for Institutional Shares, 0.12% for Investor A Shares, 0.11% for Investor A1 Shares, 0.12% for Investor C Shares and 0.06% for Class K Shares.

•

The Fund’s existing investment management agreement will be amended and restated to (a) remove the provision of administrative services and reduce each breakpoint to the contractual management fee rate schedule as follows: 0.45% of the Fund’s average daily Net Assets not exceeding $1 billion, 0.42% of the Fund’s average daily Net Assets in excess of $1 billion but not exceeding $3 billion, 0.40% of the Fund’s average daily Net Assets in excess of $3 billion but not exceeding $5 billion, 0.39% of the Fund’s average daily Net Assets in excess of $5 billion but not exceeding $10 billion, and 0.38% of the Fund’s average daily Net Assets in excess of $10 billion.

Shareholders should retain this Supplement for future reference.

PR2SAI-NYMO-1026SUP

OCTOBER 28, 2026

Summary Prospectus

BlackRock Multi-State Municipal Series Trust | Investor and Institutional Shares

●

BlackRock New York Municipal Opportunities Fund

Investor A: MENKX • Investor C: MFNKX • Institutional: MANKX

Before you invest, you may want to review the Fund’s prospectus, which contains more information about the Fund and its risks. You can find the Fund’s prospectus (including amendments and supplements), reports to shareholders and other information about the Fund, including the Fund’s statement of additional information, online at https://www.blackrock.com/prospectus. You can also get this information at no cost by calling (800) 441-7762 or by sending an e-mail request to prospectus.request@blackrock.com, or from your financial professional. The Fund’s prospectus and statement of additional information, both dated October 28, 2026, as amended and supplemented from time to time, are incorporated by reference into (legally made a part of) this Summary Prospectus.

This Summary Prospectus contains information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference.

The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Summary Prospectus. Any representation to the contrary is a criminal offense.

Not FDIC Insured ● May Lose Value ● No Bank Guarantee

Summary Prospectus

Key Facts About BlackRock New York Municipal Opportunities Fund

Investment Objective

The investment objective of the BlackRock New York Municipal Opportunities Fund (the “Fund”) is to provide shareholders with income exempt from Federal income tax and New York State and New York City personal income taxes.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell Investor and Institutional shares of the Fund. Amounts in the table are rounded to the nearest basis point, which in some cases may be “0.00.” You may pay other fees, such as brokerage commissions and other fees to your financial professional or selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each a “Financial Intermediary”), which are not reflected in the table and example below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the fund complex advised by BlackRock or its affiliates. More information about these and other discounts is available from your Financial Intermediary and in the “Details About the Share Classes” and the “Intermediary-Defined Sales Charge Waiver Policies” sections on pages 28 and A-1, respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page II-97 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)		Investor A Shares		Investor C Shares		Institutional Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)		4.25%		None		None
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower)		None1		1.00%2		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)		Investor A Shares		Investor C Shares		Institutional Shares
Management Fee3		0.47%		0.47%		0.47%
Distribution and/or Service (12b-1) Fees		0.25%		1.00%		None
Other Expenses		0.29%		0.31%		0.31%
Miscellaneous Other Expenses4,5	0.10%		0.12%		0.12%
Interest Expense	0.19%		0.19%		0.19%
Acquired Fund Fees and Expenses5		0.01%		0.01%		0.01%
Total Annual Fund Operating Expenses5		1.02%		1.79%		0.79%
Fee Waivers and/or Expense Reimbursements3,6		(0.07)%		(0.09)%		(0.09)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements3,6		0.95%		1.70%		0.70%

A contingent deferred sales charge (“CDSC”) of 1.00% is assessed on certain redemptions of Investor A Shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $250,000 or more.

There is no CDSC on Investor C Shares after one year.

As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 44, BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds (“ETFs”) managed by BlackRock or its affiliates that have a contractual management fee, through June 30, 2028. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through June 30, 2028. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested trustees of BlackRock Multi-State Municipal Series Trust (the “Trust”) or by a vote of a majority of the outstanding voting securities of the Fund.

Miscellaneous Other Expenses do not include extraordinary expenses incurred by the Fund. If included, Miscellaneous Other Expenses would have been 0.15% (for Investor A Shares), 0.17% (for Investor C Shares) and 0.17% (for Institutional Shares) of average daily net assets.

The Total Annual Fund Operating Expenses do not correlate to the ratios of expenses to average net assets given in the Fund’s most recent Annual Financial Statements and Additional Information, which includes extraordinary expenses and does not include Acquired Fund Fees and Expenses.

As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 44, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.75% (for Investor A Shares), 1.50% (for Investor C Shares) and 0.50% (for Institutional Shares) of average daily net assets through June 30, 2028. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Investor A Shares	$518	$729	$958	$1,614
Investor C Shares	$273	$555	$961	$1,895
Institutional Shares	$72	$243	$430	$970

You would pay the following expenses if you did not redeem your shares:

	1 Year	3 Years	5 Years	10 Years
Investor C Shares	$173	$555	$961	$1,895

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 28% of the average value of its portfolio.

Principal Investment Strategies of the Fund

Under normal circumstances, the Fund will invest at least 80% of its net assets, plus the amount of any borrowing for investment purposes, in investment grade New York municipal bonds and derivatives that provide investment exposure to such securities or to one or more market risk factors associated with such securities. New York municipal bonds may be obligations of a variety of issuers including governmental entities in New York and issuers located in Puerto Rico, the U.S. Virgin Islands and Guam. The interest on these obligations may not be exempt from the Federal Alternative Minimum Tax.

Municipal bonds also include short-term tax-exempt obligations, like municipal notes, variable rate demand obligations, private activity bonds and insured municipal bonds. The Fund may invest in both fixed rate and variable rate obligations.

The Fund may invest in bonds of any maturity. The Fund’s average weighted duration may vary significantly from time to time depending on the views of Fund management.

The Fund’s investment process begins with bottom-up, fundamental analysis focused on sector and security selection, and then incorporates a macroeconomic framework for evaluating and managing risk, including geographic, technical and economic risk. The Fund’s investment process is generally expected to place greater emphasis on duration management and capital structure compared to that of a more traditional municipal fixed-income fund. When selecting investments for the Fund, Fund management considers a variety of factors, including the credit quality of issuers and the yield and duration of the obligations.

The Fund is permitted to engage in transactions in derivatives, such as options or futures on a security or an index of securities (including, but not limited to, interest rate futures contracts, financial futures contracts and options thereon), for hedging purposes (including anticipatory hedges) or to seek to enhance returns. The Fund may also invest in other derivatives, such as swap agreements, including credit default swap agreements. Derivatives are financial instruments whose value is derived from another security or an index. Derivatives may allow the Fund to increase or decrease its risk exposure more quickly and efficiently than other types of instruments. The Fund may also invest in indexed and inverse floating rate obligations.

The Fund may leverage its assets through the use of proceeds received through tender option bond transactions. In a tender option bond transaction, the Fund transfers municipal bonds or other municipal securities into a special purpose entity (a “TOB Trust”). A TOB Trust typically issues two classes of beneficial interests: short-term floating rate interests (“TOB Floaters”), which are sold to third-party investors, and residual inverse floating rate interests (“TOB Residuals”), which are generally issued to the Fund. The Fund may invest in TOB Residuals and may also invest in TOB Floaters. The Fund will look through to the underlying municipal bond held by a TOB Trust for purposes of the Fund’s 80% policy.

The Fund may invest up to 20% of its assets in securities that are not New York municipal bonds (including, but not limited to, taxable municipal bonds, U.S. Treasury and Government agency issues, and investment grade corporate bonds).

The Fund may also invest up to 20% of its assets in non-investment grade municipal bonds (high yield or junk bonds), including debt securities that at the time of purchase are in default or that the Fund’s management team believes will be in default.

The Fund may also buy when-issued securities and participate in delayed delivery transactions.

The Fund may engage in active and frequent trading of portfolio securities to achieve its primary investment strategies.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks of investing in the Fund. The relative significance of each risk factor below may change over time and you should review each risk factor carefully.

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Debt Securities Risk — Debt securities, such as bonds, involve risks, such as credit risk, interest rate risk, extension risk, and prepayment risk, each of which are described in further detail below:

Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.

Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.

The Fund may be subject to a greater risk of rising interest rates during a period of low interest rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. (Duration is a measure of the price sensitivity of a debt security or portfolio of debt securities to relative changes in interest rates.) The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.

Since rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.

These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.

A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.

Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall.

Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields.

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Municipal Securities Risks — Municipal securities risks include the ability of the issuer to repay the obligation, the relative lack of information about certain issuers of municipal securities, and the possibility of future legislative changes which could affect the market for and value of municipal securities. Budgetary constraints of local, state, and federal governments upon which the issuers may be relying for funding may also impact municipal securities. These risks include:

General Obligation Bonds Risks — Timely payments depend on the issuer’s credit quality, ability to raise tax revenues and ability to maintain an adequate tax base.

Revenue Bonds Risks — These payments depend on the money earned by the particular facility or class of facilities, or the amount of revenues derived from another source.

Private Activity Bonds Risks — Municipalities and other public authorities issue private activity bonds to finance development of industrial facilities for use by a private enterprise. The private enterprise pays the principal and interest on the bond, and the issuer does not pledge its full faith, credit and taxing power for repayment.

Moral Obligation Bonds Risks — Moral obligation bonds are generally issued by special purpose public authorities of a state or municipality. If the issuer is unable to meet its obligations, repayment of these bonds becomes a moral commitment, but not a legal obligation, of the state or municipality.

Municipal Notes Risks — Municipal notes are shorter term municipal debt obligations. If there is a shortfall in the anticipated proceeds, the notes may not be fully repaid and the Fund may lose money.

Municipal Lease Obligations Risks — In a municipal lease obligation, the issuer agrees to make payments when due on the lease obligation. Although the issuer does not pledge its unlimited taxing power for payment of the lease obligation, the lease obligation is secured by the leased property.

Tax-Exempt Status Risk — The Fund and its investment manager will rely on the opinion of issuers’ bond counsel and, in the case of derivative securities, sponsors’ counsel, on the tax-exempt status of interest on municipal bonds and payments under derivative securities. Neither the Fund nor its investment manager will independently review the bases for those tax opinions, which may ultimately be determined to be incorrect and subject the Fund and its shareholders to substantial tax liabilities.

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State Specific Risk — The Fund will invest significantly in municipal securities issued by or on behalf of the State of New York and The City of New York, their political subdivisions, authorities and agencies. As a result, the Fund’s performance will be affected by the fiscal and economic health of that state, the city and their municipalities.

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Derivatives Risk — The Fund’s use of derivatives may increase its costs, reduce the Fund’s returns and/or increase volatility. Derivatives involve significant risks, including:

Leverage Risk — The Fund’s use of derivatives can magnify the Fund’s gains and losses. Relatively small market movements may result in large changes in the value of a derivatives position and can result in losses that greatly exceed the amount originally invested.

Market Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.

Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will be unable or unwilling to fulfill its contractual obligation, and the related risks of having concentrated exposure to such a counterparty.

Illiquidity Risk — The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Operational Risk — The use of derivatives includes the risk of potential operational issues, including documentation issues, settlement issues, systems failures, inadequate controls and human error.

Legal Risk — The risk of insufficient documentation, insufficient capacity or authority of counterparty, or legality or enforceability of a contract.

Volatility and Correlation Risk — Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

Valuation Risk — Valuation for derivatives may not be readily available in the market. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them.

Hedging Risk — Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences.

Tax Risk — Certain aspects of the tax treatment of derivative instruments, including swap agreements and commodity-linked derivative instruments, are currently unclear and may be affected by changes in legislation, regulations or other legally binding authority. Such treatment may be less favorable than that given to a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments.

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High Yield Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that are considered speculative and may cause income and principal losses for the Fund.

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Illiquid Investments Risk — The Fund may not acquire any illiquid investment if, immediately after the acquisition, the Fund would have invested more than 15% of its net assets in illiquid investments. An illiquid investment is any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. There can be no assurance that a security or instrument that is deemed to be liquid when purchased will continue to be liquid for as long as it is held by the Fund, and any security or instrument held by the Fund may be deemed an illiquid investment pursuant to the Fund’s liquidity risk management program. The Fund’s illiquid investments may reduce the returns of the Fund because it may be difficult to sell the illiquid investments at an advantageous time or price. In addition, if the Fund is limited in its ability to dispose of illiquid investments during periods when shareholders are redeeming or selling their shares or the Fund’s net assets otherwise shrink, the Fund will need to dispose of liquid securities to meet redemption requests and illiquid securities will become a larger portion of the Fund’s holdings. An investment may be illiquid due to, among other things, the reduced number and capacity of traditional market participants to make a market in fixed-income securities or the lack of an active trading market. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have greater exposure to the risks associated with illiquid investments. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. This may be magnified in a rising interest rate environment or other circumstances where investor redemptions or sales of Fund shares may be higher than normal. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.

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Indexed and Inverse Securities Risk — Indexed and inverse securities provide a potential return based on a particular index of value or interest rates. The Fund’s return on these securities will be subject to risk with respect to the value of the particular index. These securities are subject to leverage risk and correlation risk. Certain indexed and inverse securities have greater sensitivity to changes in interest rates or index levels than other securities, and the Fund’s investment in such instruments may decline significantly in value if interest rates or index levels move in a way Fund management does not anticipate.

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Insurance Risk — Insurance guarantees that interest payments on a municipal security will be made on time and that the principal will be repaid when the security matures. However, insurance does not protect against losses caused by declines in a municipal security’s value. The Fund cannot be certain that any insurance company will make the payments it guarantees. If a municipal security’s insurer fails to fulfill its obligations or loses its credit rating, the value of the security could drop.

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Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet the applicable requirements of the Investment Company Act of 1940, as amended (the “Investment Company Act”), and the rules thereunder. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.

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Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. An investor could lose money over short periods due to fluctuation in the Fund’s net asset value in response to short-term market movements and over longer periods during market downturns. Securities or other investments held by the Fund may underperform the markets, the relevant indices or benchmarks, or the securities selected by other funds with

similar investment objectives and investment strategies, or may otherwise fail to perform as intended. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. The success of a Fund’s activities could be affected by interest rates, availability of credit, inflation rates, economic uncertainty, changes in laws, tariffs and trade barriers, supply chain disruptions, economic sanctions, currency exchange controls, and local, regional or global events such as war, acts of terrorism, natural and environmental disasters, the spread of infectious illness or other public health issues, recessions, or other events.

Recent policy initiatives undertaken by the U.S. government have the potential to impact international relations, trade agreements and the overall regulatory environment in ways that could create uncertainty and instability in domestic and global markets, and could adversely affect the investment performance of the Fund. In particular, actions taken by the U.S. government in respect of international trade relations could lead to trade wars, increased costs for imported goods, disruptions in supply chains, reduced foreign investment, and instability in regions where the Fund invests.

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Municipal Securities Concentration Risk — From time to time the Fund may invest a substantial amount of its assets in municipal securities whose interest is paid solely from revenues of similar projects. If the Fund concentrates its investments in this manner, it assumes the legal and economic risks relating to such projects and this may have a significant impact on the Fund’s investment performance.

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Operational and Technology Risks — The Fund is directly and indirectly susceptible to operational and technology risks, including those related to human errors, processing errors, communication errors, systems failures, cybersecurity incidents, and the use of artificial intelligence and machine learning (“AI”), which may result in losses for the Fund and its shareholders or may impair the Fund’s operations. While the Fund’s service providers are required to have appropriate operational, information security and cybersecurity risk management policies and procedures, their methods of risk management may differ from those of the Fund. Operational and technology risks for the issuers in which the Fund invests could also result in material adverse consequences for such issuers and may cause the Fund’s investments in such issuers to lose value.

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Taxability Risk — Investments in taxable municipal bonds, U.S. Treasury and Government agency issues, investment grade corporate bonds and taxable money market securities as well as some of the derivatives and other instruments discussed herein will cause the Fund to have taxable investment income. The Fund may also realize capital gains on the sale of its municipal bonds (and other securities and derivatives it holds). These capital gains will be taxable regardless of whether they are derived from a sale of municipal bonds. Fund investments may also cause the Fund to recognize taxable ordinary income from market discount. The Fund will report distributions from taxable investment income, from market discount and from realized capital gains as taxable to Fund shareholders. In order for the Fund to be eligible to report distributions of tax-exempt interest income from tax-exempt or municipal securities as tax-exempt income to Fund shareholders, at least half of the Fund’s total assets must be invested in tax-exempt securities as of the end of each calendar quarter. If the Fund did not maintain that level of investment with respect to tax-exempt securities, the Fund would lose the ability to report distributions of tax-exempt interest income as tax-exempt income to Fund shareholders.

The Fund expects to use derivatives for hedging purposes or to seek to enhance returns, among other things. The Federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset. Derivatives may produce taxable income and taxable realized gain. Derivatives may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than as tax-exempt income or as capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. Payments received by the Fund from swap agreements will generally produce taxable income, while payments made by the Fund on swap agreements will be allocated against both tax-exempt and taxable gross income, decreasing the Fund’s distributable net tax-exempt income. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the Internal Revenue Service.

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Tender Option Bonds and Related Securities Risk — The Fund’s participation in tender option bond transactions may reduce the Fund’s returns and/or increase volatility. Investments in tender option bond transactions expose the Fund to counterparty risk and leverage risk. An investment in a tender option bond transaction typically will involve greater risk than an investment in a municipal fixed rate security, including the risk of loss of principal. Distributions on TOB Residuals will bear an inverse relationship to short-term municipal security interest rates. Distributions on TOB Residuals paid to the Fund will be reduced or, in the extreme, eliminated as short-term municipal interest rates rise and will increase when short-term municipal interest rates fall. TOB Residuals generally will underperform the market for fixed rate municipal securities in a rising interest rate environment. The Fund may invest in TOB Trusts on

either a non-recourse or recourse basis. If the Fund invests in a TOB Trust on a recourse basis, it could suffer losses in excess of the value of its TOB Residuals.

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U.S. Government Obligations Risk — Certain securities in which the Fund may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States. In addition, circumstances could arise that could prevent the timely payment of interest or principal on U.S. Government obligations, such as reaching the legislative “debt ceiling.” Such non-payment could result in losses to the Fund and substantial negative consequences for the U.S. economy and the global financial system.

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Variable Rate Demand Obligations Risks — Variable rate demand obligations are floating rate securities that combine an interest in a long term municipal bond with a right to demand payment before maturity from a bank or other financial institution. If the bank or financial institution is unable to pay, the Fund may lose money.

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When-Issued and Delayed Delivery Securities and Forward Commitments Risk — When-issued and delayed delivery securities and forward commitments involve the risk that the security the Fund buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation. If this occurs, the Fund may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

Performance Information

The information shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the Bloomberg Municipal Bond Index and a customized weighted index comprised of 85% Bloomberg Municipal Bond: New York Exempt Total Return Index Unhedged USD/10% Bloomberg Municipal Bond: New York High Yield (non-Investment Grade) Total Return Index/5% Bloomberg Municipal Index New York Taxable Bonds Total Return Index Value (the “Customized Reference Benchmark”). To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. If the Fund’s investment manager and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting www.blackrock.com or can be obtained by phone at (800) 882-0052.

Institutional Shares
ANNUAL TOTAL RETURNS
BlackRock New York Municipal Opportunities Fund
As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 8.13% (quarter ended December 31, 2023) and the lowest return for a quarter was -6.14% (quarter ended March 31, 2020). The year-to-date return as of September 30, 2026 was -3.21%.

For the periods ended 12/31/25 Average Annual Total Returns	1 Year	5 Years	10 Years
BlackRock New York Municipal Opportunities — Institutional Shares
Return Before Taxes	2.77 %	1.67 %	2.46 %

For the periods ended 12/31/25 Average Annual Total Returns	1 Year	5 Years	10 Years
Return After Taxes on Distributions	2.77 %	1.61 %	2.37 %
Return After Taxes on Distributions and Sale of Fund Shares	3.14 %	1.93 %	2.52 %
BlackRock New York Municipal Opportunities — Investor A Shares
Return Before Taxes	(1.94 )%	0.53 %	1.76 %
BlackRock New York Municipal Opportunities — Investor C Shares
Return Before Taxes	0.76 %	0.66 %	1.60 %
Bloomberg Municipal Bond Index (Reflects no deduction for fees, expenses or taxes)	4.25 %	0.80 %	2.34 %
Customized Reference Benchmark (Reflects no deduction for fees, expenses or taxes)	3.75 %	0.90 %	— 1

The Customized Reference Benchmark commenced in September 2016 and therefore the Customized Reference Benchmark does not have a 10-year return.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Institutional Shares only, and the after-tax returns for Investor A and Investor C Shares will vary.

Investment Manager

The Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”).

Portfolio Managers

Portfolio Manager	Portfolio Manager of the Fund Since	Title
Michael Kalinoski, CFA	2015	Director of BlackRock, Inc.
Kevin Maloney, CFA	2022	Managing Director of BlackRock, Inc.
Ryan McDonald, CFA	2023	Managing Director of BlackRock, Inc.
Christian Romaglino, CFA	2023	Director of BlackRock, Inc.
Sean Carney	2023	Managing Director of BlackRock, Inc.

Purchase and Sale of Fund Shares

You may purchase or redeem shares of the Fund each day the New York Stock Exchange is open. To purchase or sell shares you should contact your Financial Intermediary, or, if you hold your shares through the Fund, you should contact the Fund by phone at (800) 441-7762, by mail (c/o BlackRock Funds, P.O. Box 534429, Pittsburgh, Pennsylvania 15253-4429), or by the Internet at www.blackrock.com. The Fund’s initial and subsequent investment minimums generally are as follows, although the Fund may reduce or waive the minimums in some cases:

	Investor A and Investor C Shares	Institutional Shares
Minimum Initial Investment	$1,000 for all accounts except: •$50, if establishing an Automatic Investment Plan. •There is no investment minimum for employer- sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs). •There is no investment minimum for certain fee- based programs.	There is no minimum initial investment for: •Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares. •Clients of Financial Intermediaries that: (i) charge such clients a fee for advisory, investment

	Investor A and Investor C Shares	Institutional Shares
Minimum Initial Investment (continued)		consulting, or similar services or (ii) have entered into an agreement with the Fund’s distributor to offer Institutional Shares through a no-load program or investment platform. •Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with the Fund on an omnibus basis. $2 million for individuals and “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, local, city, and state governmental institutions, corporations and insurance company separate accounts who may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares. $1,000 for: •Clients investing through Financial Intermediaries that offer such shares on a platform that charges a transaction based sales commission outside of the Fund. •Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Fund’s distributor to offer Institutional Shares, and the family members of such persons.
Minimum Additional Investment	$50 for all accounts (with the exception of certain employer-sponsored retirement plans which may have a lower minimum).	No subsequent minimum.

Tax Information

The Fund’s dividends and distributions may be subject to U.S. federal income taxes and may be taxed as ordinary income or capital gains, unless you are a tax-exempt investor or are investing through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code, in which case you may be subject to U.S. federal income tax when distributions are received from such tax-deferred arrangements.

The Fund intends to make distributions most of which will be excludable from gross income for federal income tax purposes and exempt from New York state income taxes.

Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a Financial Intermediary, the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services.

These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Ask your individual financial professional or visit your Financial Intermediary’s website for more information.