(MSIF Emerging Markets Portfolio - Class IR) | (Emerging Markets Portfolio)

Investment Objective

The Emerging Markets Portfolio (the "Fund") seeks long-term capital appreciation by investing primarily in growth-oriented equity securities of issuers in emerging market countries.

Fees and Expenses

The table below describes the fees and expenses that you may pay if you buy and hold Class IR shares of the Fund. The Fund does not charge any sales loads or other fees when you purchase Class IR shares.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees - (Emerging Markets Portfolio)	Class IR ­
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	none
Maximum deferred sales charge (load) (as a percentage based on the lesser of the offering price or net asset value per share ("NAV") at redemption)	none
Redemption Fee (as a percentage of the amount redeemed on redemptions made within 30 days of purchase)	2.00%

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

Annual Fund Operating Expenses - (Emerging Markets Portfolio)	Class IR ­
Advisory Fee	0.78%
Distribution and/or Shareholder Service (12b-1) Fee	none
Other Expenses	14.00%	[1]
Total Annual Fund Operating Expenses	14.78%	[2]
Fee Waiver and/or Expense Reimbursement	13.83%	[2]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.95%	[2]

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

Expense Example - (Emerging Markets Portfolio)	1 Year	3 Years
Class IR | ­ | USD ($)	97	2,879

If You HELD Your Shares

Expense Example, No Redemption - (Emerging Markets Portfolio)	1 Year	3 Years
Class IR | ­ | USD ($)	97	2,879

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 Fund performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 35% of the average value of its portfolio.

Principal Investment Strategies

The Adviser and the Fund's "Sub-Adviser," Morgan Stanley Investment Management Company ("MSIM Company"), seek to maximize returns by investing primarily in growth-oriented equity securities in emerging markets.

The Adviser's and Sub-Adviser's investment approach combines top-down country allocation with bottom-up stock selection. The Adviser and Sub-Adviser allocate the Fund's assets among emerging markets based on relative economic, political and social fundamentals, stock valuations and investor sentiment. To manage risk, the Adviser and/or Sub-Adviser emphasize macroeconomic and fundamental research.

The investment process takes into account information about environmental, social and governance issues (also referred to as ESG) when making investment decisions. The Adviser and/or Sub-Adviser focus on engaging company management around corporate governance practices as well as what the Adviser and/or Sub-Adviser deem to be materially important environmental and/or social issues facing a company.

Under normal circumstances, at least 80% of the Fund's assets will be invested in equity securities of issuers located in emerging market countries. This policy may be changed without shareholder approval; however, you would be notified upon 60 days' notice in writing of any changes. The Adviser and/or Sub-Adviser generally consider selling an investment when they determine the company 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 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:

• 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 and political conditions.

• Foreign and Emerging Market Securities. Investments in foreign markets entail special risks such as currency, political, economic and market risks. There also may be greater market volatility, less reliable financial information, 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 ongoing 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, entities and/or individuals, changes in international trading patterns, trade barriers and other protectionist or retaliatory measures. Economic sanctions could, among other things, effectively restrict or eliminate the Fund's ability to purchase or sell securities or groups of securities for a substantial period of time, and may make the Fund's investments in such securities harder to value. 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. 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 could reduce or preclude the opportunity for gain if the value of the currency moves 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.

• Liquidity. The Fund's investments in restricted and illiquid securities may entail greater risk than investments in other types of securities. These securities may be more difficult to sell, particularly in times of market turmoil. Additionally, the market for certain investments deemed liquid at the time of purchase may become illiquid under adverse market or economic conditions. Illiquid securities may be more difficult to value. If the Fund is forced to sell an illiquid 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.

• Derivatives. A derivative instrument often has risks similar to its underlying asset and may have 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 and risks that the transactions may not be liquid. Certain derivative transactions may give rise to a form of leverage. Leverage magnifies the potential for gain and the risk of loss.

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.

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 IS 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 a broad measure of market performance, as well as an index that represents a group of similar mutual funds, over time. 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 (800) 548-7786.

Annual Total Returns—Calendar Years

High Quarter	03/31/17	11.33%
Low Quarter	09/30/15	-13.90%

Average Annual Total Returns (for the calendar periods ended December 31, 2017)

Average Annual Total Returns - (Emerging Markets Portfolio) - ­		Past One Year	Since Inception		Inception Date
Class IS	[1]	35.09%	5.54%		Sep. 13, 2013
Class IS | Return After Taxes on Distributions	[1],[2]	35.04%	5.04%		Sep. 13, 2013
Class IS | Return After Taxes on Distributions and Sale of Fund Shares	[1]	20.21%	4.36%		Sep. 13, 2013
Class IR	[1]
MSCI Emerging Markets Net Index (reflects no deduction for fees, expenses or taxes)	[3]	37.28%	6.21%	[4]
Lipper Emerging Market Funds Index (reflects no deduction for taxes)	[5]	35.56%	6.24%	[4]

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 Class IR shares will vary from Class IS 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.

[1] Other Expenses have been estimated for the current fiscal year.

[2] 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 certain investment related expenses, taxes, interest and other extraordinary expenses (including litigation), will not exceed 0.95% for Class IR. The fee waivers and/or expense reimbursements will continue for at least one year 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.

[1] Class IS shares are not offered in the Prospectus. Class IR shares of the Fund had not commenced investment operations as of December 31, 2017. Class IR shares would have similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Return information for the Fund's Class IR shares will be shown in future prospectuses offering the Fund's Class IR shares after the Fund's Class IR shares have a full calendar year of return information to report.

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

[3] The MSCI Emerging Markets Net Index is a free float-adjusted market capitalization weighted index that is designed to measure equity market performance of emerging markets. 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 MSCI Emerging Markets Net Index currently consists of 24 emerging market country indices. 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.

[4] Since Inception reflects the inception date of Class IS.

[5] The Lipper Emerging Market Funds Index is an equally-weighted performance index of the largest qualifying funds (based on net assets) in the Lipper Emerging Market Funds classification. There are currently 30 funds represented in this Index.