Exhibit (a)(115)

MORGAN STANLEY INSTITUTIONAL FUND, INC.

ARTICLES SUPPLEMENTARY

MORGAN STANLEY INSTITUTIONAL FUND, INC., a Maryland corporation (the “Corporation”), does hereby certify to the State Department of Assessments and Taxation of Maryland (the “Department”) that:

FIRST: The Corporation is registered as an open-end investment company under the Investment Company Act of 1940.

SECOND: The Board of Directors of the Corporation (the “Board of Directors”), at a meeting duly convened and held on March 11-12, 2026, adopted resolutions which:

(a) authorized the elimination of one (1) portfolio of common stock of the Corporation, consisting of five (5) classes, designated as Emerging Markets ex China Portfolio – Class I, Emerging Markets ex China Portfolio – Class A, Emerging Markets ex China Portfolio – Class R6, Emerging Markets ex China Portfolio – Class C and Emerging Markets ex China Portfolio – Class IR (the “Liquidated Portfolio”), none of which portfolio or classes have any shares outstanding; and

(b) authorized the reduction to zero of the number of shares of common stock classified as shares of the Liquidated Portfolio.

THIRD: The reduction to zero of the number of shares of the Liquidated Portfolio results in the decrease in the aggregate number of shares of common stock which the Corporation has authority to issue from eighty-three billion three hundred and seventy-five million (83,375,000,000) shares of common stock to eighty billion two hundred and fifty million (80,250,000,000) shares of common stock.

FOURTH: As of immediately before the decrease in the number of authorized shares of common stock of the Liquidated Portfolio and the aggregate number of authorized shares of common stock of all classes of the Corporation, as set forth above, the total number of shares of common stock of all classes that the Corporation had authority to issue was eighty-three billion three hundred and seventy-five million (83,375,000,000) shares of common stock, par value $0.001 per share, having an aggregate par value of eighty-three million three hundred and seventy-five thousand dollars ($83,375,000) and designated and classified in the following portfolios and classes:

FIFTH: After giving effect to the decrease in the number of authorized shares of common stock of the Liquidated Portfolio and the aggregate number of authorized shares of common stock of all classes of the Corporation, as set forth above, the total number of shares of common stock of all classes that the Corporation has authority to issue is eighty billion two hundred and fifty million (80,250,000,000) shares of common stock, par value $0.001 per share, having an aggregate par value of eighty million two hundred and fifty thousand dollars ($80,250,000) and designated and classified in the following portfolios and classes:

SIXTH: The number of shares of common stock of the Liquidated Portfolio, and the aggregate number of shares of common stock of all classes that the Corporation has authority to issue, has been decreased by the Board of Directors in accordance with Section 2-105(c) of the Maryland General Corporation Law.

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IN WITNESS WHEREOF, the Corporation has caused these Articles Supplementary to be signed in its name and on its behalf by its Vice President and attested to on its behalf by its Assistant Secretary on this 24^th day of April, 2026.

THE UNDERSIGNED, Vice President of MORGAN STANLEY INSTITUTIONAL FUND, INC., who executed on behalf of the Corporation the foregoing Articles Supplementary of which this certificate is made a part, hereby acknowledges, in the name and on behalf of the Corporation, the foregoing Articles Supplementary to be the corporate act of the Corporation and, as to all matters or facts required to be verified under oath, the undersigned Vice President acknowledges that to the best of his knowledge, information and belief, these matters and facts are true in all material respects and that this statement is made under the penalties for perjury.