(MSIF International Advantage Portfolio - Class IS) | (International Advantage Portfolio)

Investment Objective

The International Advantage 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 and hold Class IS shares of the Fund. The Fund does not charge any sales loads or other fees when you purchase Class IS shares.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees - (International Advantage Portfolio)	Class IS ­
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 - (International Advantage Portfolio)	Class IS ­
Advisory Fee	0.80%
Distribution and/or Shareholder Service (12b-1) Fee	none
Other Expenses	14.09%	[1]
Total Annual Fund Operating Expenses	14.89%	[2]
Fee Waiver and/or Expense Reimbursement	13.94%	[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 - (International Advantage Portfolio)	1 Year	3 Years
Class IS | ­ | USD ($)	97	2,897

If You HELD Your Shares

Expense Example, No Redemption - (International Advantage Portfolio)	1 Year	3 Years
Class IS | ­ | USD ($)	97	2,897

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 30% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Adviser seeks to achieve the Fund's investment objective by investing primarily in established companies on an international basis, with capitalizations within the range of companies included in the MSCI All Country World ex USA Index.

The Adviser emphasizes a bottom-up stock selection process, seeking attractive investments on an individual company basis. In selecting securities for investment, the Adviser seeks high-quality established companies that the Adviser believes are undervalued at the time of purchase. The Adviser typically favors companies it believes have sustainable competitive advantages that can be monetized through growth. The investment process integrates analysis of sustainability with respect to disruptive change, financial strength, environmental and social externalities and governance (also referred to as ESG). The Adviser generally considers selling a portfolio holding when it determines that the holding no longer satisfies its investment criteria.

The Fund may invest in foreign securities, which may include emerging market securities. Under normal market conditions, the Fund typically invests at least 80% of its assets in the securities of issuers located outside of the United States. The Fund may invest in equity securities. The Fund may also invest in privately placed and restricted securities.

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. 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.

• 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.

• Focused Investing. To the extent that the Fund invests in a limited number of issuers, the Fund will be more susceptible to negative events affecting those issuers and a decline in the value of a particular instrument may cause the Fund's overall value to decline to a greater degree than if the Fund were invested more widely.

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 I shares' performance from year-to-year and by showing how the Fund's average annual returns for the past one and five year periods 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	14.69%
Low Quarter	09/30/11	-15.54%

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

Average Annual Total Returns - (International Advantage Portfolio) - ­		Past One Year	Past Five Years	Since Inception		Inception Date
Class I	[1]	44.75%	13.58%	12.34%		Dec. 28, 2010
Class I | Return After Taxes on Distributions	[1],[2]	43.90%	12.10%	11.21%		Dec. 28, 2010
Class I | Return After Taxes on Distributions and Sale of Fund Shares	[1]	25.74%	10.43%	9.71%		Dec. 28, 2010
Class IS	[1]
MSCI All Country World ex USA Net Index (reflects no deduction for fees, expenses or taxes)	[3]	27.19%	6.80%	5.09%	[4]
Lipper International Multi-Cap Growth Funds Index (reflects no deduction for taxes)	[5]	28.88%	7.59%	5.85%	[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 IS shares will vary from Class I 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 IS. 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 I shares are not offered in the Prospectus. Class IS shares of the Fund had not commenced operations as of December 31, 2017. Class IS shares would have substantially 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. The returns for Class IS shares are expected to be higher than the returns for Class I shares of the Fund as expenses of Class IS shares are estimated to be lower. Return information for the Fund's Class IS shares will be shown in future prospectuses offering the Fund's Class IS shares after the Fund's Class IS 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 All Country World ex USA Net 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.

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

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