Morgan Stanley Institutional Fund, Inc.

Passport Overseas Equity Portfolio

Summary Prospectus | April 30, 2024

Share Class and Ticker Symbol

Class IR

MAIHX

Before you invest, you may want to review the Fund’s statutory prospectus (“Prospectus”), which contains more information about the Fund and its risks. You can find the Fund’s Prospectus and other information about the Fund, including the Statement of Additional Information (“SAI”) and the most recent Annual and Semi-Annual Reports to Shareholders (“Shareholder Reports”), online at www.morganstanley.com/im/MSIFPassportOverseasEquityIR. You can also get this information at no cost by calling toll-free 1-866-414-6349 or by sending an e-mail request to orders@mysummaryprospectus.com. The Fund’s Prospectus and SAI, both dated April 30, 2024 (as may be supplemented from time to time), are incorporated by reference into this Summary Prospectus.

Investment Objective

The Passport Overseas Equity Portfolio (the “Fund”) seeks long-term capital appreciation.

Fees and Expenses

The table below describes the fees and expenses that you may pay if you buy, hold and sell Class IR shares of the Fund. The Fund does not charge any sales loads or other fees when you purchase or redeem Class IR shares. You may pay fees other than the fees and expenses of the Fund, such as brokerage commissions and other fees charged by financial intermediaries, which are not reflected in the tables and examples below.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)


	Class IR
Advisory Fee	0.65%
Distribution and/or Shareholder Service (12b-1) Fee	None
Other Expenses	18.97%
Total Annual Fund Operating Expenses¹	19.62%
Fee Waiver and/or Expense Reimbursement¹	18.77%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement¹	0.85%

Morgan Stanley Institutional Fund, Inc. Prospectus | Fund Summary

Passport Overseas Equity Portfolio (Con’t)

Example

The example below 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, your investment has a 5% return each year and the Fund’s operating expenses remain the same (except that the example incorporates the fee waiver and/or expense reimbursement arrangement for only the first year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:


If You SOLD Your Shares
	1 Year	3 Years	5 Years	10 Years
Class IR	$87	$3,598	$6,157	$9,918


If You HELD Your Shares
	1 Year	3 Years	5 Years	10 Years
Class IR	$87	$3,598	$6,157	$9,918

The Fund’s “Adviser,” Morgan Stanley Investment Management Inc., has agreed to reduce its advisory fee and/or reimburse the Fund so that Total Annual Fund Operating Expenses, excluding acquired fund fees and expenses (as applicable), certain investment related expenses, taxes, interest and other extraordinary expenses (including litigation), will not exceed 0.85% for Class IR. The fee waivers and/or expense reimbursements will continue for at least one year from the date of this Prospectus or until such time as the Board of Directors of Morgan Stanley Institutional Fund, Inc. (the “Company”) acts to discontinue all or a portion of such waivers and/or reimbursements when it deems such action is appropriate.

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 Fund shares are held in a taxable account. These costs, which are not reflected in Total 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 14% of the average value of its portfolio.

Principal Investment Strategies

The Adviser actively selects among developed and emerging countries applying its investment process to determine a country’s future economic growth and equity return potential. The Adviser’s approach combines a top-down country process with sector allocation and bottom-up stock selection. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in the equity securities of issuers located outside of the United States. This policy may be changed without shareholder approval; however, you would be notified upon 60 days’ notice in writing of any changes.

The Adviser analyzes the global economic environment and each country’s fundamentals and actively allocate the Fund’s assets among countries and sectors located throughout the world (the investment universe is developed markets, including the United States, and emerging markets, including frontier markets). Investment decisions may be implemented through sector, industry and stock-specific allocations within and across markets that best capture the top-down view. Country and sector weightings are based on relative economic, political and social fundamentals, stock valuations and investor sentiment and are a function of the Adviser’s conviction levels, the size of the economy and liquidity. The investment process considers analysis of sustainability with respect to financial strength, environmental and social factors and governance (also referred to as ESG).

Investments are based on fundamental analysis in an effort to identify those equities that stand to benefit most from the Adviser’s current and prospective macro views and that are likely to experience attractive earnings growth prospects as a result of exposure and gearing to those top-down conditions. Investment decisions are implemented by equity positions in sectors, industries, customized baskets and/or individual stocks. The equity securities in which the Fund may invest include common stock, preferred stock, convertible securities, depositary receipts, rights and warrants. The Adviser generally considers selling a portfolio holding when they determine that the position no longer satisfies their investment criteria.

The Fund may, but it is not required to, use derivative instruments for a variety of purposes, including hedging, risk management, portfolio management or to earn income. The Fund’s use of derivatives may involve the purchase and sale of derivative instruments such as futures, options, swaps, contracts for difference (“CFDs”) and other related instruments and techniques. The Fund may utilize foreign currency forward exchange contracts, which are also derivatives, in connection with its investments in foreign securities. Derivative instruments used by the Fund will be counted toward the Fund’s 80% policy discussed above to the extent they have economic characteristics similar to the securities included within that policy.

Principal Risks

There is no assurance that the Fund will achieve its investment objective, and you can lose money investing in this Fund. The principal risks of investing in the Fund include:

Morgan Stanley Institutional Fund, Inc. Prospectus | Fund Summary

Passport Overseas Equity Portfolio (Con’t)

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Equity Securities. In general, prices of equity securities are more volatile than those of fixed-income securities. The prices of equity securities fluctuate, and sometimes widely fluctuate, in response to activities specific to the issuer of the security as well as factors unrelated to the fundamental condition of the issuer, including general market, economic, political conditions and public health conditions. During periods when equity securities experience heightened volatility, such as during periods of market, economic or financial uncertainty or distress, the Fund’s investments in equity securities may be subject to heightened risks.

The value of equity securities and related instruments may decline in response to adverse changes in the economy or the economic outlook; deterioration in investor sentiment; interest rate, currency, and commodity price fluctuations; adverse geopolitical, social or environmental developments; issuer- and sector-specific considerations; unexpected trading activity among retail investors; and other factors. Market conditions may affect certain types of stocks to a greater extent than other types of stocks. If the stock market declines, the value of Fund shares will also likely decline.

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Convertible Securities. A convertible security is a bond, debenture, note, preferred stock, right, warrant or other security that may be converted into or exchanged for a prescribed amount of common stock or other security of the same or a different issuer or into cash within a particular period of time at a specified price or formula. To the extent that the Fund invests in convertible securities, and the convertible security’s investment value is greater than its conversion value, its price will be likely to increase when interest rates fall and decrease when interest rates rise. If the conversion value exceeds the investment value, the price of the convertible security will tend to fluctuate directly with the price of the underlying security.

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Foreign and Emerging Market Securities. Investments in foreign markets entail special risks such as currency, political (including geopolitical), economic and market risks. There also may be greater market volatility, less reliable financial information, less stringent investor protections and disclosure standards, higher transaction and custody costs, decreased market liquidity and less government and exchange regulation associated with investments in foreign markets. In addition, investments in certain foreign markets that have historically been considered stable may become more volatile and subject to increased risk due to developments and changing conditions in such markets. Moreover, the growing interconnectivity of global economies and financial markets has increased the probability that adverse developments and conditions in one country or region will affect the stability of economies and financial markets in other countries or regions. Certain foreign markets may rely heavily on particular industries or foreign capital and are more vulnerable to diplomatic developments, the imposition of economic sanctions against a particular country or countries, organizations, companies, entities and/or individuals, changes in international trading patterns, trade barriers and other protectionist or retaliatory measures. Investments in foreign markets may also be adversely affected by governmental actions such as the imposition of capital controls, nationalization of companies or industries, expropriation of assets or the imposition of punitive taxes. The governments of certain countries may prohibit or impose substantial restrictions on foreign investing in their capital markets or in certain sectors or industries. In addition, a foreign government may limit or cause delay in the convertibility or repatriation of its currency which would adversely affect the U.S. dollar value and/or liquidity of investments denominated in that currency. Certain foreign investments may become less liquid in response to market developments or adverse investor perceptions, or become illiquid after purchase by the Fund, particularly during periods of market turmoil. When the Fund holds illiquid investments, its portfolio may be harder to value. The risks of investing in emerging market countries are greater than the risks associated with investments in foreign developed countries. Certain emerging market countries may be subject to less stringent requirements regarding accounting, auditing, financial reporting and record keeping and therefore, material information related to an investment may not be available or reliable. In addition, the Fund is limited in its ability to exercise its legal rights or enforce a counterparty’s legal obligations in certain jurisdictions outside of the United States, in particular, in emerging market countries. In addition, the Fund’s investments in foreign issuers may be denominated in foreign currencies and therefore, to the extent unhedged, the value of those investments will fluctuate with U.S. dollar exchange rates. To the extent hedged by the use of foreign currency forward exchange contracts, the precise matching of the foreign currency forward exchange contract amounts and the value of the securities involved will not generally be possible because the future value of such securities in foreign currencies will change as a consequence of market movements in the value of those securities between the date on which the contract is entered into and the date it matures. There is additional risk that such transactions may reduce or preclude the opportunity for gain if the value of the currency should move in the direction opposite to the position taken and that foreign currency forward exchange contracts create exposure to currencies in which the Fund’s securities are not denominated. The use of foreign currency forward exchange contracts involves the risk of loss from the insolvency or bankruptcy of the counterparty to the contract or the failure of the counterparty to make payments or otherwise comply with the terms of the contract. Economic sanctions or other similar measures may be, and have been, imposed against certain countries, organizations, companies, entities and/or individuals. Economic sanctions and other similar measures could, among other things, effectively restrict or eliminate the Fund’s ability to purchase or sell securities, negatively impact the value or liquidity of the Fund’s investments, significantly delay or prevent the settlement of the Fund’s securities transactions, force the Fund to sell or otherwise dispose of investments at inopportune times or prices, or impair the Fund’s ability to meet its investment objective or invest in accordance with its investment strategies.

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Variable Interest Entities. Chinese operating companies sometimes rely on variable interest entity (“VIE”) structures to raise capital from non-Chinese investors because of Chinese government limitations or prohibitions on direct foreign ownership in certain industries. In a VIE structure, a series of contractual arrangements are entered into between a holding company domiciled outside of China and a Chinese operating company or companies, which are intended to mimic direct ownership in the operating

Morgan Stanley Institutional Fund, Inc. Prospectus | Fund Summary

Passport Overseas Equity Portfolio (Con’t)

company, but in many cases these arrangements have not been tested in court and it is not clear that the contracts are enforceable or that the structures will otherwise work as intended. The offshore holding company, which is not a Chinese operating company, then issues exchange-traded shares that are sold to the public, including non-Chinese investors (such as the Fund). Shares of the offshore entity purchased by the Fund would not be equity ownership interests in the Chinese operating company and the Fund’s interest would be subject to legal, operational and other risks associated with the company’s use of the VIE structure. For example, at any time the Chinese government could determine that the contractual arrangements constituting part of the VIE structure are unenforceable or do not comply with applicable law or regulations, these laws or regulations could change or be interpreted differently in the future, and the Chinese government may with no advance notice otherwise intervene in or exert influence over VIE structures or the related Chinese operating companies. If any of these or similar risks or developments materialize, the Fund’s investment in the offshore entity may suddenly and significantly decline in value or become worthless because of, among other things, difficulty enforcing (or the inability to enforce) the contractual arrangements or materially adverse effects on the Chinese operating company’s performance. In these circumstances, the Fund could experience significant losses with no recourse available. From time to time, the Fund’s investments in U.S.-listed shell companies relying on VIE structures to consolidate China-based operations could be significant.

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Liquidity. The Fund may make investments that are less liquid, illiquid or restricted or that may become illiquid or less liquid in response to overall economic conditions or adverse investor perceptions, and which may entail greater risk than investments in other types of securities. These investments may be more difficult to value or sell, particularly in times of market turmoil, and there may be little trading in the secondary market available for particular securities. If the Fund is forced to sell an illiquid or restricted security to fund redemptions or for other cash needs, it may be forced to sell the security at a loss or for less than its fair value and may be unable to sell the security at all.

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Derivatives. Derivatives and other similar instruments that create synthetic exposure often are subject to risks similar to those of the underlying asset or instrument, including market risk, and may be subject to additional risks, including imperfect correlation between the value of the derivative and the underlying asset, risks of default by the counterparty to certain transactions, magnification of losses incurred due to changes in the market value of the securities, instruments, indices or interest rates to which the derivative instrument relates, risks that the transactions may not be liquid, risks arising from margin and payment requirements, risks arising from mispricing or valuation complexity and operational and legal risks. Certain derivatives transactions may give rise to a form of leverage. Leverage magnifies the potential for gain and the risk of loss.

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Market and Geopolitical Risk. The value of your investment in the Fund is based on the values of the Fund’s investments, which change due to economic and other events that affect markets generally, as well as those that affect particular regions, countries, industries, companies or governments. These events may be sudden and unexpected, and could adversely affect the liquidity of the Fund’s investments, which may in turn impact valuation, the Fund’s ability to sell securities and/or its ability to meet redemptions. The risks associated with these developments may be magnified if certain social, political, economic and other conditions and events (such as war, natural disasters, epidemics and pandemics, terrorism, conflicts, social unrest, recessions, inflation, interest rate changes and supply chain disruptions) adversely interrupt the global economy and financial markets. It is difficult to predict when events affecting the U.S. or global financial markets may occur, the effects that such events may have and the duration of those effects (which may last for extended periods). These events may negatively impact broad segments of businesses and populations and have a significant and rapid negative impact on the performance of the Fund’s investments, adversely affect and increase the volatility of the Fund’s share price and exacerbate pre-existing risks to the Fund.

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Active Management Risk. In pursuing the Fund’s investment objective, the Adviser has considerable leeway in deciding which investments to buy, hold or sell on a day-to-day basis, and which trading strategies to use. For example, the Adviser, in its discretion, may determine to use some permitted trading strategies while not using others. The success or failure of such decisions will affect the Fund’s performance.

Shares of the Fund are not bank deposits and are not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Morgan Stanley Institutional Fund, Inc. Prospectus | Fund Summary

Passport Overseas Equity Portfolio (Con’t)

Performance Information

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s Class IR shares’ performance from year-to-year and by showing how the Fund’s average annual returns for the past one year period and since inception compare with those of an index intended to measure broad market performance. The Fund changed its name from Active International Allocation Portfolio to Passport Overseas Equity Portfolio effective May 31, 2023. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available online at www.morganstanley.com/im or by calling toll-free 1-800-869-6397.

Annual Total Returns—Calendar Years


High Quarter	12/31/20	22.26%
Low Quarter	03/31/20	-21.66%

Average Annual Total Returns

(for the calendar periods ended December 31, 2023)


	Past One Year	Since Inception
Class IR (commenced operations on 10/31/2019)
Return Before Taxes	12.49%	5.80%
Return After Taxes on Distributions¹	11.74%	4.88%
Return After Taxes on Distributions and Sale of Fund Shares	8.18%	4.48%
MSCI All Country World ex USA Index (reflects no deduction for fees, expenses or taxes)²	15.62%	4.88%³

1	These returns do not reflect any tax consequences from a sale of your shares at the end of each period.

The MSCI All Country World ex USA Index is a free float-adjusted market capitalization weighted index designed to measure the equity market performance of developed and emerging markets, excluding the United States. The term “free float” represents the portion of shares outstanding that are deemed to be available for purchase in the public equity markets by investors. The performance of the index is listed in U.S. dollars and assumes reinvestment of net dividends. Net total return indices reinvest dividends after the deduction of withholding taxes, using (for international indices) a tax rate applicable to non-resident institutional investors who do not benefit from double taxation treaties. It is not possible to invest directly in an index.

3	Since Inception reflects the inception date of Class IR.

The after-tax returns shown in the table above are calculated using the historical highest individual federal marginal income tax rates during the period shown and do not reflect the impact of state and local taxes. After-tax returns for the Fund’s other classes will vary from Class IR shares’ returns. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and after-tax returns are not relevant to investors who hold their Fund shares through tax deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns may be higher than before-tax returns due to an assumed benefit from capital losses that would have been realized had Fund shares been sold at the end of the relevant periods, as applicable.

Fund Management

Adviser. Morgan Stanley Investment Management Inc.

Portfolio Managers. The Fund is managed by members of the Passport Equity team. Information about the members primarily responsible for the day-to-day management of the Fund is shown below:


Name	Title with Adviser	Date Began Managing Fund
Ben V. Rozin	Executive Director of the Adviser	April 2017
Jitania Kandhari	Managing Director of the Adviser	April 2017

Morgan Stanley Institutional Fund, Inc. Prospectus | Fund Summary

Passport Overseas Equity Portfolio (Con’t)

Purchase and Sale of Fund Shares

To purchase Class IR shares, an investor must meet a minimum initial investment of $5 million or be a defined contribution, defined benefit or other employer sponsored employee benefit plan, in each case provided that the plan trades through an intermediary that combines its clients’ assets in a single omnibus account, whether or not such plan is qualified under the Internal Revenue Code of 1986, as amended (the “Code”), and in each case subject to the discretion of the Adviser. The minimum initial investment may be waived for certain investments. For more information, please refer to the section of the Prospectus entitled “Shareholder Information—Minimum Investment Amounts.”

Shares of the Fund may be purchased or sold on any day the New York Stock Exchange (“NYSE”) is open for business directly from the Fund by mail (c/o SS&C Global Investor and Distribution Solutions, Inc., P.O. Box 219804, Kansas City, MO 64121-9804), by telephone (1-800-869-6397) or by contacting an authorized third-party, such as a broker-dealer or other financial intermediary that has entered into a selling agreement with the Fund’s “Distributor,” Morgan Stanley Distribution, Inc. (each, a “Financial Intermediary”). For more information, please refer to the sections of the Prospectus entitled “Shareholder Information—How To Purchase Fund Shares” and “—How To Redeem Fund Shares.”

Tax Information

The Fund intends to make distributions that may be taxed as ordinary income or capital gains, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Class IR shares of the Fund through a Financial Intermediary (such as a bank), the Adviser and/or the Distributor may pay the Financial Intermediary for the sale of Class IR shares and related services. These payments, which may be significant in amount, may create a conflict of interest by influencing the Financial Intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary’s web site for more information. For additional information about the Fund’s revenue sharing arrangements for Class IR shares, see the section of the Statement of Additional Information entitled “Revenue Sharing.”

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