N-CSRS

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act File Number: 811-09631                                

Cohen & Steers Institutional Realty Shares, Inc.

(Exact name of registrant as specified in charter)

280 Park Avenue, New York, NY 10017

(Address of principal executive offices) (Zip code)

Dana A. DeVivo

Cohen & Steers Capital Management, Inc.

280 Park Avenue

New York, New York 10017

(Name and address of agent for service)

Registrant’s telephone number, including area code: (212) 832-3232                                

Date of fiscal year end: December 31                                

Date of reporting period: June 30, 2021                                

Item 1. Reports to Stockholders.

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

To Our Shareholders:

We would like to share with you our report for the six months ended June 30, 2021. The total returns for Cohen & Steers Institutional Realty Shares, Inc. (the Fund) and its comparative benchmarks were:

	Six Months Ended June 30, 2021
Cohen & Steers Institutional Realty Shares		21.56	%
FTSE Nareit All Equity REITs Indexa		21.35	%
S&P 500 Indexa		15.25	%

The performance data quoted represent past performance. Past performance is no guarantee of future results. The investment return and the principal value of an investment will fluctuate and shares, if redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data quoted. Current total returns of the Fund can be obtained by visiting our website at cohenandsteers.com. The Fund’s returns assume the reinvestment of all dividends and distributions at net asset value (NAV). Fund performance reflects fee waivers and/or expense reimbursements, without which the performance would have been lower. Index performance does not reflect the deduction of any fees, taxes or expenses. An investor cannot invest directly in an index. Performance figures for periods shorter than one year are not annualized.

Please note that distributions paid by the Fund to shareholders are subject to recharacterization for tax purposes and are taxable up to the amount of the Fund’s investment company taxable income and net realized gains. Distributions in excess of the Fund’s investment company taxable income and net realized gains are a return of capital distributed from the Fund’s assets.

Market Review

In the six-month period ended June 30, 2021, U.S. real estate securities continued to rally from their lows in early 2020, as progress in vaccine distribution allowed for a general lifting of restrictions on public gatherings, business activities and travel. Economic reopening and additional fiscal relief led to increasing activity, generating stronger demand for real estate. Supply growth in many property sectors slowed amid labor shortages and rising construction costs, giving landlords greater pricing power to negotiate rents. Borrowing costs for many public real estate companies remained near historical lows. These positive conditions drove improving investor optimism, resulting in higher earnings multiples.

Fund Performance

The Fund had a positive total return in the period and outperformed its benchmark.

Returns were positive across all property types. The regional mall and shopping center sectors were among the strongest performers, as easing virus concerns led to a sharp rise in foot traffic and retail sales from depressed levels. The Fund’s overweight in regional malls aided relative performance, although the benefit was partly countered by the effect of our underweight in shopping centers.

^a  The FTSE Nareit All Equity REITs Index contains all tax-qualified REITs with more than 50% of total assets in qualifying real estate assets other than mortgages secured by real property that also meet minimum size and liquidity criteria. The S&P 500 Index is an unmanaged index of 500 large-capitalization stocks that is frequently used as a general measure of U.S. stock market performance.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

Self storage, which had been one of the more resilient sectors through the pandemic, continued to see strong demand amid continued moving activity, driving rates for new customers up 50–70% from 2020 levels. The Fund’s overweight in self storage companies contributed positively to performance.

Hotel companies as a group lagged the broader REIT market in the period but had a solid absolute return, benefiting from massive pent-up demand, with resort and leisure destinations outperforming more business-oriented hotels in urban locations. Stock selection in hotels helped the Fund’s performance, due largely to sizable gains in Boyd Gaming and Caesars Entertainment, two out-of-benchmark companies focused on gaming activities.

Leasing trends for apartments in U.S. coastal markets have bounced back fast and Sunbelt markets remained exceptionally strong, fueled by strong housing demand. Our underweight and stock selection in apartments detracted from relative performance. The Fund did not invest in Avalon Bay Communities and Equity Residential, which both gained more than 30% in the period.

Infrastructure and industrial REITs, which were among the few sectors to advance in 2020, added to those gains in the period but slightly trailed the index. The Fund’s underweight in infrastructure aided performance, although stock selection in industrial hindered relative performance. We were overweight Americold Realty Trust, a food-focused industrial company that had only a modest gain.

Elsewhere of note, stock selection in the health care sector detracted from performance. We were overweight Healthpeak Properties, which had sold its senior housing operating portfolio and as a result benefited less from the reopening of the economy. Our underweight in offices, which underperformed amid an uncertain outlook for return to office trends, contributed to performance.

Sincerely,

JON CHEIGH	JASON A. YABLON
Portfolio Manager	Portfolio Manager

MATHEW KIRSCHNER

Portfolio Manager

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

The views and opinions in the preceding commentary are subject to change without notice and are as of the date of the report. There is no guarantee that any market forecast set forth in the commentary will be realized. This material represents an assessment of the market environment at a specific point in time, should not be relied upon as investment advice and is not intended to predict or depict performance of any investment.

Visit Cohen & Steers online at cohenandsteers.com

For more information about the Cohen & Steers family of mutual funds, visit cohenandsteers.com. Here you will find fund net asset values, fund fact sheets and portfolio highlights, as well as educational resources and timely market updates.

Our website also provides comprehensive information about Cohen & Steers, including our most recent press releases, profiles of our senior investment professionals and their investment approach to each asset class. The Cohen & Steers family of mutual funds specializes in liquid real assets, including real estate securities, listed infrastructure and natural resource equities, as well as preferred securities and other income solutions.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

Performance Review (Unaudited)

Average Annual Total Returns—For Periods Ended June 30, 2021

	1 Year			5 Years			10 Years			Since Inceptiona
Cohen & Steers Institutional Realty Shares, Inc.		35.96	%		9.41	%		10.47	%		12.14	%

The performance data quoted represent past performance. Past performance is no guarantee of future results. The investment return and principal value of an investment will fluctuate and shares, if redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance data quoted. Performance information current to the most recent month end can be obtained by visiting our website at cohenandsteers.com. Total return assumes the reinvestment of all dividends and distributions at NAV. The performance table does not reflect the deduction of taxes that a shareholder would pay on Fund distributions or the redemption of Fund shares. During the periods presented above, the investment manager waived fees and/or reimbursed expenses. Without this arrangement, performance would have been lower.

The annualized gross and net expense ratios, respectively, were 0.76% and 0.75% as disclosed in the May 1, 2021 prospectus. The investment manager has contractually agreed to waive its fee and/or reimburse expenses so that the Fund’s total annual operating expenses as reflected in the Fund’s financial statements (excluding brokerage fees and commissions, taxes, certain other expenses and upon approval of the Board of Directors, extraordinary expenses) never exceed 0.75% of the average daily net assets of the Fund. This commitment is currently expected to remain in place for the life of the Fund, can only be amended or terminated by agreement of the Fund’s Board of Directors and the investment manager and will terminate automatically in the event of termination of the investment management agreement between the Fund and the investment manager.

^a  Inception date of February 14, 2000.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

Expense Example (Unaudited)

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs and (2) ongoing costs including investment management fees and other Fund expenses. This example is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period January 1, 2021—June 30, 2021.

Actual Expenses

The first line of the following table provides information about actual account values and expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first line under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second line of the following table provides information about hypothetical account values and hypothetical expenses based on the Fund’s actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund’s actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing cost of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transaction costs. Therefore, the second line of the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.

	Beginning Account Value January 1, 2021		Ending Account Value June 30, 2021		Expenses Paid During Perioda January 1,  2021— June 30, 2021
Actual (21.56% return)	$	1,000.00	$	1,215.60	$	4.12
Hypothetical (5% annual return before expenses)	$	1,000.00	$	1,021.08	$	3.76

^a  Expenses are equal to the Fund’s annualized net expense ratio of 0.75% multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period).

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

June 30, 2021 Top Ten Holdings^a (Unaudited)

Security	Value		% of Net Assets
American Tower Corp.	$	603,791,265		10.4
Public Storage		441,656,779		7.6
Simon Property Group, Inc.		335,532,712		5.8
Duke Realty Corp.		292,970,644		5.1
Healthpeak Properties, Inc.		289,547,665		5.0
Equinix, Inc.		269,813,253		4.7
UDR, Inc.		240,956,718		4.2
SBA Communications Corp.		237,418,752		4.1
Extra Space Storage, Inc.		223,379,710		3.9
Weyerhaeuser Co.		208,742,155		3.6

^a  Top ten holdings (excluding short-term investments) are determined on the basis of the value of individual securities held.

Sector Breakdown

(Based on Net Assets)

(Unaudited)

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

SCHEDULE OF INVESTMENTS

June 30, 2021 (Unaudited)

		Shares		Value
COMMON STOCK	99.1%
COMMUNICATIONS—TOWERS	16.6%
American Tower Corp.			2,235,105	$	603,791,265
Crown Castle International Corp.			628,396		122,600,059
SBA Communications Corp.			744,960		237,418,752
					963,810,076
CONSUMER, CYCLICAL—HOTELS, RESTAURANTS & LEISURE	2.3%
Boyd Gaming Corp.a			1,158,310		71,224,482
Caesars Entertainment, Inc.a			607,447		63,022,626
					134,247,108
REAL ESTATE	80.2%
DATA CENTERS	9.1%
CyrusOne, Inc.			1,839,618		131,569,479
Digital Realty Trust, Inc.			851,253		128,079,526
Equinix, Inc.			336,174		269,813,253
					529,462,258
HEALTH CARE	12.1%
Healthcare Trust of America, Inc., Class A			2,079,044		55,510,475
Healthpeak Properties, Inc.			8,697,737		289,547,665
Medical Properties Trust, Inc.			3,168,118		63,679,172
Ventas, Inc.			2,175,494		124,220,707
Welltower, Inc.			2,060,710		171,245,001
					704,203,020
HOTEL	3.6%
Host Hotels & Resorts, Inc.a			9,813,925		167,719,978
Park Hotels & Resorts, Inc.a			2,067,901		42,619,440
					210,339,418
INDUSTRIALS	9.9%
Americold Realty Trust			2,856,216		108,107,775
BG LLH, LLC (Lineage Logistics)b			310,885		24,457,284
Duke Realty Corp.			6,187,342		292,970,644
Prologis, Inc.			1,220,709		145,911,347
					571,447,050

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

SCHEDULE OF INVESTMENTS—(Continued)

June 30, 2021 (Unaudited)

		Shares		Value
NET LEASE	6.7%
Realty Income Corp.			205,345	$	13,704,725
Spirit Realty Capital, Inc.			2,067,336		98,901,354
VEREIT, Inc.			3,648,707		167,585,113
VICI Properties, Inc.			3,400,120		105,471,723
					385,662,915
OFFICE	1.3%
Highwoods Properties, Inc.			1,612,088		72,818,015
REAL ESTATE SERVICES	1.8%
Jones Lang LaSalle, Inc.a			545,744		106,671,122
RESIDENTIAL	12.1%
APARTMENT	9.6%
Apartment Income REIT Corp.			2,830,231		134,237,856
Essex Property Trust, Inc.			605,793		181,743,958
UDR, Inc.			4,919,492		240,956,718
					556,938,532
MANUFACTURED HOME	2.5%
Sun Communities, Inc.			837,979		143,629,601
TOTAL RESIDENTIAL					700,568,133
SELF STORAGE	11.5%
Extra Space Storage, Inc.			1,363,568		223,379,710
Public Storage			1,468,811		441,656,779
					665,036,489
SHOPPING CENTERS	8.5%
COMMUNITY CENTER	2.7%
Federal Realty Investment Trust			516,369		60,502,956
Kimco Realty Corp.			2,832,148		59,050,286
SITE Centers Corp.			2,683,617		40,415,272
					159,968,514
REGIONAL MALL	5.8%
Simon Property Group, Inc.			2,571,526		335,532,712
TOTAL SHOPPING CENTERS					495,501,226

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

SCHEDULE OF INVESTMENTS—(Continued)

June 30, 2021 (Unaudited)

		Shares		Value
TIMBER	3.6%
Weyerhaeuser Co.			6,064,560	$	208,742,155
TOTAL REAL ESTATE					4,650,451,801
TOTAL COMMON STOCK (Identified cost—$4,260,059,588)					5,748,508,985
SHORT-TERM INVESTMENTS	1.1%
MONEY MARKET FUNDS
State Street Institutional Treasury Money Market Fund, Premier Class, 0.01%c			61,581,829		61,581,829
TOTAL SHORT-TERM INVESTMENTS (Identified cost—$61,581,829)					61,581,829
TOTAL INVESTMENTS IN SECURITIES (Identified cost—$4,321,641,417)	100.2%				5,810,090,814
LIABILITIES IN EXCESS OF OTHER ASSETS	(0.2)				(10,845,148	)
NET ASSETS (Equivalent to $52.22 per share based on 111,047,208 shares of common stock outstanding)	100.0%			$	5,799,245,666

Glossary of Portfolio Abbreviations

REIT Real Estate Investment Trust

Note: Percentages indicated are based on the net assets of the Fund.

^a  Non-income producing security.

^b  Restricted security. Aggregate holdings equal 0.4% of the net assets of the Fund. This security was acquired on August 3, 2020, at a cost of $19,103,906 ($62.50 per share). Security value is determined based on significant unobservable inputs (Level 3).

^c  Rate quoted represents the annualized seven-day yield.

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

STATEMENT OF ASSETS AND LIABILITIES

June 30, 2021 (Unaudited)

ASSETS:
Investments in securities, at value (Identified cost—$4,321,641,417)	$	5,810,090,814
Receivable for:
Investment securities sold		50,819,820
Fund shares sold		16,093,193
Dividends		14,393,144
Other assets		197,874
Total Assets		5,891,594,845
LIABILITIES:
Payable for:
Fund shares redeemed		84,189,383
Investment management fees		3,586,013
Investment securities purchased		2,381,561
Dividends declared		2,186,835
Other liabilities		5,387
Total Liabilities		92,349,179
NET ASSETS applicable to 111,047,208 shares of $0.001 par value of common stock outstanding	$	5,799,245,666
NET ASSET VALUE PER SHARE:
($5,799,245,666 ÷ 111,047,208 shares outstanding)	$	52.22
NET ASSETS consist of:
Paid-in capital	$	4,366,414,991
Total distributable earnings/(accumulated loss)		1,432,830,675
	$	5,799,245,666

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

STATEMENT OF OPERATIONS

For the Six Months Ended June 30, 2021 (Unaudited)

Investment Income:
Dividend income	$	44,523,477
Expenses:
Investment management fees		18,137,388
Registration and filing fees		113,249
Directors’ fees and expenses		77,198
Miscellaneous		13,968
Total Expenses		18,341,803
Reduction of Expenses (See Note 2)		(204,415	)
Net Expenses		18,137,388
Net Investment Income (Loss)		26,386,089
Net Realized and Unrealized Gain (Loss):
Net realized gain (loss) on investments in securities		135,898,077
Net change in unrealized appreciation (depreciation) on investments in securities		802,675,934
Net Realized and Unrealized Gain (Loss)		938,574,011
Net Increase (Decrease) in Net Assets Resulting from Operations	$	964,960,100

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

STATEMENT OF CHANGES IN NET ASSETS (Unaudited)

	For the Six Months Ended June 30, 2021			For the Year Ended December 31, 2020
Change in Net Assets:
From Operations:
Net investment income (loss)	$	26,386,089		$	69,542,520
Net realized gain (loss)		135,898,077			(177,915,674	)
Net change in unrealized appreciation (depreciation)		802,675,934			61,719,743
Net increase (decrease) in net assets resulting from operations		964,960,100			(46,653,411	)
Distributions to Shareholders		(43,627,867	)		(178,304,687	)
Tax Return of Capital to Shareholders		—			(8,749,663	)
Total distributions		(43,627,867	)		(187,054,350	)
Capital Stock Transactions:
Increase (decrease) in net assets from Fund share transactions		959,147,862			440,378,889
Total increase (decrease) in net assets		1,880,480,095			206,671,128
Net Assets:
Beginning of period		3,918,765,571			3,712,094,443
End of period	$	5,799,245,666		$	3,918,765,571

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

FINANCIAL HIGHLIGHTS (Unaudited)

The following table includes selected data for a share outstanding throughout each period and other performance information derived from the financial statements. It should be read in conjunction with the financial statements and notes thereto.

	For the Six Months Ended June 30, 2021			For the Year Ended December 31,
Per Share Operating Data:				2020			2019			2018			2017			2016
Net asset value, beginning of period		$43.31			$46.89			$39.25			$43.32			$43.18			$45.93
Income (loss) from investment operations:
Net investment income (loss)a		0.26			0.80			0.84			0.93			0.79			0.83
Net realized and unrealized gain (loss)		9.06			(2.25	)		11.80			(2.51	)b		2.37			1.87
Total from investment operations		9.32			(1.45	)		12.64			(1.58	)		3.16			2.70
Less dividends and distributions to shareholders from:
Net investment income		(0.41	)		(1.03	)		(0.63	)		(0.75	)		(0.86	)		(0.82	)
Net realized gain		—			(1.00	)		(4.37	)		(1.74	)		(2.16	)		(4.63	)
Tax return of capital		—			(0.10	)		—			—			—			—
Total dividends and distributions to shareholders		(0.41	)		(2.13	)		(5.00	)		(2.49	)		(3.02	)		(5.45	)
Net increase (decrease) in net asset value		8.91			(3.58	)		7.64			(4.07	)		0.14			(2.75	)
Net asset value, end of period		$52.22			$43.31			$46.89			$39.25			$43.32			$43.18
Total returnc		21.56	%d		–2.57	%		33.01	%		–4.01	%b		7.47	%		5.91	%

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

FINANCIAL HIGHLIGHTS (Unaudited)—(Continued)

	For the Six Months Ended June 30, 2021			For the Year Ended December 31,
Ratios/Supplemental Data:				2020			2019			2018			2017			2016
Net assets, end of period (in millions)		$5,799.2			$3,918.8			$3,712.1			$2,659.6			$2,787.9			$2,740.8
Ratios to average daily net assets:
Expenses (before expense reduction)		0.76	%e		0.76	%		0.76	%		0.78	%b		0.77	%		0.76	%
Expenses (net of expense reduction)		0.75	%e		0.75	%		0.75	%		0.77	%b		0.75	%		0.75	%
Net investment income (loss) (before expense reduction)		1.08	%e		1.93	%		1.81	%		2.22	%		1.77	%		1.77	%
Net investment income (loss) (net of expense reduction)		1.09	%e		1.94	%		1.82	%		2.23	%		1.79	%		1.78	%
Portfolio turnover rate		19	%d		66	%		82	%		68	%		76	%		79	%

^a  Calculation based on average shares outstanding.

^b  During the reporting period the Fund settled legal claims against two issuers of securities previously held by the Fund. As a result, the net realized and unrealized gain (loss) on investments per share includes proceeds received from the settlements. Without these proceeds the net realized and unrealized gain (loss) on investments per share would have been $(2.56). Additionally, the expense ratio includes extraordinary expenses related to the direct action. Without these expenses, the ratio of expenses to average daily net assets (before expense reduction and net of expense reduction) would have been 0.76% and 0.75%, respectively. Excluding the proceeds from and expenses relating to the settlements, the total return would have been -4.12%.

^c  Return assumes the reinvestment of all dividends and distributions at net asset value.

^d  Not annualized.

^e  Annualized.

See accompanying notes to financial statements.

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

NOTES TO FINANCIAL STATEMENTS (Unaudited)

Note 1. Organization and Significant Accounting Policies

Cohen & Steers Institutional Realty Shares, Inc. (the Fund) was incorporated under the laws of the State of Maryland on October 13, 1999 and is registered under the Investment Company Act of 1940 (the 1940 Act) as a non-diversified, open-end management investment company. The Fund’s investment objective is total return.

The following is a summary of significant accounting policies consistently followed by the Fund in the preparation of its financial statements. The Fund is an investment company and, accordingly, follows the investment company accounting and reporting guidance of the Financial Accounting Standards Board Accounting Standards Codification (ASC) Topic 946—Investment Companies. The accounting policies of the Fund are in conformity with accounting principles generally accepted in the United States of America (GAAP). The preparation of the financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates.

Portfolio Valuation: Investments in securities that are listed on the New York Stock Exchange (NYSE) are valued, except as indicated below, at the last sale price reflected at the close of the NYSE on the business day as of which such value is being determined. If there has been no sale on such day, the securities are valued at the mean of the closing bid and ask prices on such day or, if no ask price is available, at the bid price.

Securities not listed on the NYSE but listed on other domestic or foreign securities exchanges (including NASDAQ) are valued in a similar manner. Securities traded on more than one securities exchange are valued at the last sale price reflected at the close of the exchange representing the principal market for such securities on the business day as of which such value is being determined.

Readily marketable securities traded in the over-the-counter (OTC) market, including listed securities whose primary market is believed by Cohen & Steers Capital Management, Inc. (the investment manager) to be OTC, are valued on the basis of prices provided by a third-party pricing service or third-party broker-dealers when such prices are believed by the investment manager, pursuant to delegation by the Board of Directors, to reflect the fair value of such securities.

Short-term debt securities with a maturity date of 60 days or less are valued at amortized cost, which approximates fair value. Investments in open-end mutual funds are valued at net asset value (NAV).

The policies and procedures approved by the Fund’s Board of Directors delegate authority to make fair value determinations to the investment manager, subject to the oversight of the Board of Directors. The investment manager has established a valuation committee (Valuation Committee) to administer, implement and oversee the fair valuation process according to the policies and procedures approved annually by the Board of Directors. Among other things, these procedures allow the Fund to utilize independent pricing services, quotations from securities and financial instrument dealers and other market sources to determine fair value.

Securities for which market prices are unavailable, or securities for which the investment manager determines that the bid and/or ask price or a counterparty valuation does not reflect market value, will

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

be valued at fair value, as determined in good faith by the Valuation Committee, pursuant to procedures approved by the Fund’s Board of Directors. Circumstances in which market prices may be unavailable include, but are not limited to, when trading in a security is suspended, the exchange on which the security is traded is subject to an unscheduled close or disruption or material events occur after the close of the exchange on which the security is principally traded. In these circumstances, the Fund determines fair value in a manner that fairly reflects the market value of the security on the valuation date based on consideration of any information or factors it deems appropriate. These may include, but are not limited to, recent transactions in comparable securities, information relating to the specific security and developments in the markets.

For equity securities, including restricted securities, where observable inputs are limited, assumptions about market activity and risk are used and these securities would be categorized as Level 2 or 3 in the hierarchy, depending on the relative significance of the valuation inputs. Securities, including private placements or other restricted securities, for which observable inputs are not available are valued using alternate valuation approaches, including the market approach, the income approach and cost approach, and are categorized as Level 3 in the hierarchy. The market approach considers factors including the price of recent investments in the same or a similar security or financial metrics of comparable securities. The income approach considers factors including expected future cash flows, security specific risks and corresponding discount rates. The cost approach considers factors including the value of the security’s underlying assets and liabilities.

The Fund’s use of fair value pricing may cause the NAV of Fund shares to differ from the NAV that would be calculated using market quotations. Fair value pricing involves subjective judgments and it is possible that the fair value determined for a security may be materially different than the value that could be realized upon the sale of that security.

Fair value is defined as the price that the Fund would expect to receive upon the sale of an investment or expect to pay to transfer a liability in an orderly transaction with an independent buyer in the principal market or, in the absence of a principal market, the most advantageous market for the investment or liability. The hierarchy of inputs that are used in determining the fair value of the Fund’s investments is summarized below.

• Level 1—quoted prices in active markets for identical investments

• Level 2—other significant observable inputs (including quoted prices for similar investments, interest rates, credit risk, etc.)

• Level 3—significant unobservable inputs (including the Fund’s own assumptions in determining the fair value of investments)

The inputs or methodology used for valuing investments may or may not be an indication of the risk associated with those investments. Changes in valuation techniques may result in transfers into or out of an assigned level within the disclosure hierarchy.

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

The following is a summary of the inputs used as of June 30, 2021 in valuing the Fund’s investments carried at value:

	Total		Quoted Prices in Active Markets for Identical Investments (Level 1)		Other Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Common Stock:
Real Estate—Industrials	$	571,447,050	$	546,989,766	$	—	$	24,457,284	a
Other Industries		5,177,061,935		5,177,061,935		—		—
Short-Term Investments		61,581,829		—		61,581,829		—
Total Investments in Securitiesb	$	5,810,090,814	$	5,724,051,701	$	61,581,829	$	24,457,284

^a  Restricted security, where observable inputs are limited, has been fair valued by the Valuation Committee, pursuant to the Fund’s fair value procedures and classified as Level 3 security.

^b  Portfolio holdings are disclosed individually on the Schedule of Investments.

The following is a reconciliation of investments for which significant unobservable inputs (Level 3) were used in determining fair value:

	Common Stock—Real Estate—Industrials
Balance as of December 31, 2020	$	18,691,262
Purchases		355,113	a
Change in unrealized appreciation (depreciation)		5,410,909
Balance as of June 30, 2021	$	24,457,284

The change in unrealized appreciation (depreciation) attributable to securities owned on June 30, 2021 which were valued using significant unobservable inputs (Level 3) amounted to $5,410,909.

^a  Represents additional shares acquired through dividend reinvestment.

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

The following table summarizes the quantitative inputs and assumptions used for investments categorized in Level 3 of the fair value hierarchy.

	Fair Value at June 30, 2021		Valuation Technique	Unobservable Inputs	Amount	Valuation Impact from an Increase in Inputa
Common Stock— Real Estate— Industrials	$	24,457,284	Market Comparable Companies	Enterprise Value/ EBITDAb Multiple Liquidity Discount	24.8x 15%	Increase Decrease

^a  Represents the directional change in the fair value of the Level 3 investments that could have resulted from an increase in the corresponding input as of period end. A decrease to the unobservable input would have had the opposite effect. Significant changes in these inputs may result in a materially higher or lower fair value measurement.

^b  Earnings Before Interest, Taxes, Depreciation and Amortization.

Security Transactions and Investment Income: Security transactions are recorded on trade date. Realized gains and losses on investments sold are recorded on the basis of identified cost. Interest income, which includes the amortization of premiums and accretion of discounts, is recorded on the accrual basis. Dividend income is recorded on the ex-dividend date. Distributions from REITs are recorded as ordinary income, net realized capital gain or return of capital based on information reported by the REITs and management’s estimates of such amounts based on historical information. These estimates are adjusted when the actual source of distributions is disclosed by the REITs and actual amounts may differ from the estimated amounts.

Dividends and Distributions to Shareholders: Dividends from net investment income and capital gain distributions are determined in accordance with U.S. federal income tax regulations, which may differ from GAAP. Dividends from net investment income, if any, are declared and paid quarterly. Net realized capital gains, unless offset by any available capital loss carryforward, are typically distributed to shareholders at least annually. Dividends and distributions to shareholders are recorded on the ex-dividend date and are automatically reinvested in full and fractional shares of the Fund based on the NAV per share at the close of business on the payable date, unless the shareholder has elected to have them paid in cash.

Dividends from net investment income are subject to recharacterization for tax purposes. Based upon the results of operations for the six months ended June 30, 2021, the investment manager considers it likely that a portion of the dividends will be reclassified to distributions from net realized gain and/or tax return of capital upon the final determination of the Fund’s taxable income after December 31, 2021, the Fund’s fiscal year end.

Income Taxes: It is the policy of the Fund to continue to qualify as a regulated investment company (RIC), if such qualification is in the best interest of the shareholders, by complying with the requirements of Subchapter M of the Internal Revenue Code applicable to RICs, and by distributing substantially all of its taxable earnings to its shareholders. Also, in order to avoid the payment of any federal excise taxes, the Fund will distribute substantially all of its net investment income and net

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

realized gains on a calendar year basis. Accordingly, no provision for federal income or excise tax is necessary. Management has analyzed the Fund’s tax positions taken on federal and applicable state income tax returns as well as its tax positions in non-U.S. jurisdictions in which it trades for all open tax years and has concluded that as of June 30, 2021, no additional provisions for income tax are required in the Fund’s financial statements. The Fund’s tax positions for the tax years for which the applicable statutes of limitations have not expired are subject to examination by the Internal Revenue Service, state departments of revenue and by foreign tax authorities.

Note 2. Investment Management Fees and Other Transactions with Affiliates

Investment Management Fees: Cohen & Steers Capital Management, Inc. serves as the Fund’s investment manager pursuant to an investment management agreement (the investment management agreement). Under the terms of the investment management agreement, the investment manager provides the Fund with day-to-day investment decisions and generally manages the Fund’s investments in accordance with the stated policies of the Fund, subject to the supervision of the Board of Directors.

For the services provided to the Fund, the investment manager receives a fee, accrued daily and paid monthly, at the annual rate of 0.75% of the average daily net assets of the Fund.

The investment manager is also responsible, under the investment management agreement, for the performance of certain administrative functions for the Fund. Additionally, the investment manager pays certain expenses of the Fund, including, but not limited to, administrative and custody fees, transfer agent fees, professional fees, and reports to shareholders.

The investment manager has contractually agreed to waive its fee and/or reimburse the Fund so that the Fund’s total annual operating expenses as reflected in the Fund’s financial statements (excluding brokerage fees and commissions, taxes, certain other expenses and upon approval of the Board of Directors, extraordinary expenses) never exceed 0.75% of the average daily net assets of the Fund. This commitment is currently expected to remain in place for the life of the Fund, can only be amended or terminated by agreement of the Fund’s Board of Directors and the investment manager and will terminate automatically in the event of termination of the investment management agreement between the investment manager and the Fund. For the six months ended June 30, 2021, fees waived and/or expenses reimbursed totaled $204,415.

Directors’ and Officers’ Fees: Certain directors and officers of the Fund are also directors, officers, and/or employees of the investment manager. The Fund does not pay compensation to directors and officers affiliated with the investment manager.

Other: As of June 30, 2021, approximately 13% of the Fund’s outstanding shares were owned by shareholders investing either directly or indirectly through an account, platform or program sponsored by one financial institution. Investment and asset allocation decisions by either a direct shareholder or financial institution regarding the account, platform or program through which multiple shareholders invest may result in subscription and redemption decisions that have a significant impact on the assets, expenses and trading activities of the Fund. Such a decision may cause the Fund to sell assets at disadvantageous times or prices, and may negatively affect the Fund’s NAV and performance.

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

Note 3. Purchases and Sales of Securities

Purchases and sales of securities, excluding short-term investments, for the six months ended June 30, 2021, totaled $1,876,379,616 and $918,403,876, respectively.

Note 4. Income Tax Information

As of June 30, 2021, the federal tax cost and net unrealized appreciation (depreciation) in value of investments held were as follows:

Cost of investments in securities for federal income tax purposes	$	4,321,641,417
Gross unrealized appreciation on investments	$	1,488,935,261
Gross unrealized depreciation on investments		(485,864	)
Net unrealized appreciation (depreciation) on investments	$	1,488,449,397

As of December 31, 2020, the Fund has a net capital loss carryforward of $127,518,123 which may be used to offset future capital gains. These losses are a short-term capital loss carryforward of $127,518,123, which under current federal income tax rules, may offset capital gains recognized in any future period.

Note 5. Capital Stock

On March 17, 2020, the Board of Directors of the Fund approved an increase to the Fund’s authorized shares of capital stock. The Fund is now authorized to issue 150 million shares of capital stock, at a par value of $0.001 per share. The Fund’s Board of Directors may increase or decrease the aggregate number of shares of common stock that the Fund has authority to issue. Transactions in Fund shares were as follows:

	For the Six Months Ended June 30, 2021						For the Year Ended December 31, 2020
	Shares			Amount			Shares			Amount
Sold		30,086,134		$	1,421,424,656			34,792,964		$	1,387,240,514
Issued as reinvestment of dividends and distributions		796,558			39,492,035			4,189,397			165,267,604
Redeemed		(10,318,010	)		(501,768,829	)		(27,673,363	)		(1,112,129,229	)
Net increase (decrease)		20,564,682		$	959,147,862			11,308,998		$	440,378,889

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

Note 6. Other Risks

Common Stock Risk: While common stocks have historically generated higher average returns than fixed-income securities over the long-term, common stocks have also experienced significantly more volatility in those returns, although under certain market conditions, fixed-income investments may have comparable or greater price volatility. The value of common stocks and other equity securities will fluctuate in response to developments concerning the company, political and regulatory circumstances, the stock market, and the economy. In the short term, stock prices can fluctuate dramatically in response to these developments. Different parts of the market and different types of equity securities can react differently to these developments. For example, stocks of large companies can react differently than stocks of smaller companies, and value stocks (stocks of companies that are undervalued by various measures and have potential for long-term capital appreciation), can react differently from growth stocks (stocks of companies with attractive cash flow returns on invested capital and earnings that are expected to grow). These developments can affect a single company, all companies within the same industry, economic sector or geographic region, or the stock market as a whole.

Real Estate Market Risk: Since the Fund concentrates its assets in companies engaged in the real estate industry, an investment in the Fund will be closely linked to the performance of the real estate markets. Risks of investing in real estate securities include falling property values due to increasing vacancies, declining rents resulting from economic, legal, tax, political or technological developments, lack of liquidity, limited diversification, and sensitivity to certain economic factors such as interest-rate changes and market recessions. Real estate company prices also may drop because of the failure of borrowers to pay their loans and poor management, and residential developers, in particular, could be negatively impacted by falling home prices, slower mortgage origination and rising construction costs. The risks of investing in REITs are similar to those associated with direct investments in real estate securities.

REIT Risk: In addition to the risks of securities linked to the real estate industry, REITs are subject to certain other risks related to their structure and focus. REITs are dependent upon management skills and generally may not be diversified. REITs are also subject to heavy cash flow dependency, defaults by borrowers and self-liquidation. In addition, REITs could possibly fail to (i) qualify for pass-through of income under applicable tax law, or (ii) maintain their exemptions from registration under the 1940 Act. The above factors may also adversely affect a borrower’s or a lessee’s ability to meet its obligations to the REIT. In the event of a default by a borrower or lessee, the REIT may experience delays in enforcing its rights as a mortgagee or lessor and may incur substantial costs associated with protecting its investments.

Small- and Medium-Sized Companies Risk: Real estate companies in the industry tend to be small- to medium-sized companies in relation to the equity markets as a whole. There may be less trading in a smaller company’s stock, which means that buy and sell transactions in that stock could have a larger impact on the stock’s price than is the case with larger company stocks. Smaller companies also may have fewer lines of business so that changes in any one line of business may have a greater impact on a smaller company’s stock price than is the case for a larger company. Further, smaller company stocks may perform differently in different cycles than larger company stocks.

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

Accordingly, real estate company shares can, and at times will, perform differently than large company stocks.

Non-Diversification Risk: As a “non-diversified” investment company, the Fund can invest in fewer individual companies than a diversified investment company. As a result, the Fund is more susceptible to any single political, regulatory or economic occurrence and to the financial condition of individual issuers in which it invests. The Fund’s relative lack of diversity may subject investors to greater risk of loss than a fund that has a diversified portfolio.

Geopolitical Risk: Occurrence of global events similar to those in recent years, such as war, terrorist attacks, natural or environmental disasters, country instability, infectious disease epidemics, such as that caused by the COVID-19 virus, market instability, debt crises and downgrades, embargoes, tariffs, sanctions and other trade barriers and other governmental trade or market control programs, the potential exit of a country from its respective union and related geopolitical events, may result in market volatility and may have long-lasting impacts on both the U.S. and global financial markets. Additionally, those events, as well as other changes in foreign and domestic political and economic conditions, could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, secondary trading, credit ratings, inflation, investor sentiment and other factors affecting the value of the Fund’s investments.

An outbreak of respiratory disease caused by a novel coronavirus designated as COVID-19 has resulted in, among other things, extreme volatility in the financial markets and severe losses, reduced liquidity of many instruments, significant travel restrictions, significant disruptions to business operations, supply chains and customer activity, lower consumer demand for goods and services, service and event cancellations, reductions and other changes, strained healthcare systems, as well as general concern and uncertainty. The impact of the COVID-19 outbreak has negatively affected the global economy, the economies of individual countries, and the financial performance of individual issuers, sectors, industries, asset classes, and markets in significant and unforeseen ways. Pandemics may also exacerbate other pre-existing political, social, economic, market and financial risks. The effects of the outbreak in developing or emerging market countries may be greater due to less established health care systems and supply chains. The COVID-19 pandemic and its effects may result in a sustained economic downturn or a global recession, ongoing market volatility and/or decreased liquidity in the financial markets, exchange trading suspensions and closures, higher default rates, domestic and foreign political and social instability and damage to diplomatic and international trade relations. While some vaccines have been developed and approved for use by various governments, the political, social, economic, market and financial risks of COVID-19 could persist for years to come. The foregoing could impair the Fund’s ability to maintain operational standards (such as with respect to satisfying redemption requests), disrupt the operations of the Fund’s service providers, adversely affect the value and liquidity of the Fund’s investments, and negatively impact the Fund’s performance and your investment in the Fund.

On January 31, 2020, the United Kingdom (UK) withdrew from the European Union (EU) (referred to as Brexit), commencing a transition period that ended on December 31, 2020. On January 1, 2021, the EU-UK Trade and Cooperation Agreement, a bilateral trade and cooperation deal governing the future relationship between the UK and the EU, provisionally went into effect. The UK Parliament ratified

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

the agreement in December 2020 and the EU Parliament ratified the agreement in April 2021. The agreement must now be approved by EU member states to enter into force officially. Brexit has resulted in volatility in European and global markets and could have negative long-term impacts on financial markets in the UK and throughout Europe. There is considerable uncertainty about the potential consequences of Brexit, the EU-UK Trade and Cooperation Agreement, how future negotiations of trade relations will proceed, and how the financial markets will react to all of the preceding. As this process unfolds, markets may be further disrupted. Given the size and importance of the UK’s economy, uncertainty about its legal, political and economic relationship with the remaining member states of the EU may continue to be a source of instability.

Growing tensions, including trade disputes, between the United States and other nations, or among foreign powers, and possible diplomatic, trade or other sanctions could adversely impact the global economy, financial markets and the Fund. The strengthening or weakening of the U.S. dollar relative to other currencies may, among other things, adversely affect the Fund’s investments denominated in non-U.S. dollar currencies. It is difficult to predict when similar events affecting the U.S. or global financial markets may occur, the effects that such events may have, and the duration of those effects.

Regulatory Risk: The U.S. government has proposed and adopted multiple regulations that could have a long-lasting impact on the Fund and on the mutual fund industry in general. The U.S. Securities and Exchange Commission’s (SEC) final rules, related requirements and amendments to modernize reporting and disclosure, along with other potential upcoming regulations, could, among other things, restrict the Fund’s ability to engage in transactions, impact flows into the Fund and/or increase overall expenses of the Fund. In addition, the SEC, Congress, various exchanges and regulatory and self-regulatory authorities, both domestic and foreign, have undertaken reviews of the use of derivatives by registered investment companies, which could affect the nature and extent of instruments used by the Fund. While the full extent of all of these regulations is still unclear, these regulations and actions may adversely affect both the Fund and the instruments in which the Fund invests and its ability to execute its investment strategy. Similarly, regulatory developments in other countries may have an unpredictable and adverse impact on the Fund.

The SEC has recently adopted a rule relating to a registered investment company’s use of derivatives and similar transactions that could potentially require the Fund to observe more stringent requirements than are currently imposed by the 1940 Act. The new rule will replace present SEC and SEC staff regulatory guidance related to limits on a registered investment company’s use of derivative instruments and certain other transactions, such as short sales and reverse repurchase agreements. The rule may substantially curtail the Fund’s ability to use derivative instruments as part of the Fund’s investment strategy and could ultimately prevent the Fund from being able to achieve its investment goals.

Large Shareholder Risk: The Fund may have one or more large shareholders or a group of shareholders investing in Fund shares indirectly through an account, platform or program sponsored by a financial institution. Investment and asset allocation decisions by such financial institutions regarding the account, platform or program through which multiple shareholders invest may result in subscription and redemption decisions that have a significant impact on the assets, expenses and trading activities

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NOTES TO FINANCIAL STATEMENTS (Unaudited)—(Continued)

of the Fund. Such a decision may cause the Fund to sell assets (or invest cash) at disadvantageous times or prices, increase or accelerate taxable gains or transaction costs and may negatively affect the Fund’s NAV, performance, or ability to satisfy redemptions in a timely manner.

This is not a complete list of the risks of investing in the Fund. For additional information concerning the risks of investing in the Fund, please consult the Fund’s prospectus.

Note 7. Other

In the normal course of business, the Fund enters into contracts that provide general indemnifications. The Fund’s maximum exposure under these arrangements is dependent on claims that may be made against the Fund in the future and, therefore, cannot be estimated; however, based on experience, the risk of material loss from such claims is considered remote.

Note 8. Subsequent Events

Management has evaluated events and transactions occurring after June 30, 2021 through the date that the financial statements were issued, and has determined that no additional disclosure in the financial statements is required.

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OTHER INFORMATION

A description of the policies and procedures that the Fund uses to determine how to vote proxies relating to portfolio securities is available (i) without charge, upon request, by calling 800-330-7348, (ii) on our website at cohenandsteers.com or (iii) on the SEC’s website at http://www.sec.gov. In addition, the Fund’s proxy voting record for the most recent 12-month period ended June 30 is available by August 31 of each year (i) without charge, upon request, by calling 800-330-7348 or (ii) on the SEC’s website at http://www.sec.gov.

Disclosures of the Fund’s complete holdings are required to be made monthly on Form N-PORT, with every third month made available to the public by the SEC 60 days after the end of the Fund’s fiscal quarter. The Fund’s Form N-PORT is available (i) without charge, upon request, by calling 800-330-7348 or (ii) on the SEC’s website at http://www.sec.gov.

Please note that distributions paid by the Fund to shareholders are subject to recharacterization for tax purposes and are taxable up to the amount of the Fund’s investment company taxable income and net realized gains. Distributions in excess of the Fund’s net investment company taxable income and realized gains are a return of capital distributed from the Fund’s assets. The final tax treatment of all distributions is reported to shareholders on their 1099-DIV forms, which are mailed after the close of each calendar year.

Changes to the Portfolio Management Team

Effective May 1, 2021, Thomas Bohjalian no longer serves as a portfolio manager of the Fund. Jon Cheigh, Jason Yablon and Mathew Kirschner continue to serve as portfolio managers of the Fund.

Changes to the Board of Directors

On March 8, 2021, the Board of Directors voted to set the number of directors on the Fund’s Board of Directors to ten. In addition, the Board of Directors elected Ms. Ramona Rogers-Windsor as a Director of the Fund.

Ramona Rogers-Windsor: In addition to serving as a Director of the Cohen & Steers funds, Ms. Rogers-Windsor serves as a member of the Capital Southwest Board of Directors since March 2021 and a member of the Thomas Jefferson University Board of Trustees since December 2020. Previously, Ms. Rogers-Windsor spent over 23 years in investment management with Northwestern Mutual Investment Company, LLC, most recently as Managing Director and Portfolio Manager. Prior to that, Ms. Rogers-Windsor served as a financial officer with Northwestern Mutual Life. Ms. Rogers-Windsor has over 38 years of experience across multiple segments of the financial services industry and has previously served on the boards of several non-profit organizations. Ms. Rogers-Windsor holds a BS in Accounting from Marquette University and is a Certified Public Accountant and a Chartered Financial Analyst charterholder.

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APPROVAL OF INVESTMENT MANAGEMENT AGREEMENT

The Board of Directors of the Fund, including a majority of the directors who are not parties to the Fund’s investment management agreement (the Management Agreement), or interested persons of any such party (the Independent Directors), has the responsibility under the Investment Company Act of 1940 to approve the Fund’s Management Agreement for its initial two year term and its continuation annually thereafter at a meeting of the Board of Directors called for the purpose of voting on the approval or continuation. The Management Agreement was discussed at a meeting of the Independent Directors, in their capacity as the Contract Review Committee, held on June 8, 2021 and at meetings of the full Board of Directors held on March 16, 2021 and June 15, 2021. The Independent Directors, in their capacity as the Contract Review Committee, also discussed the Management Agreement in executive session on June 15, 2021. At the meeting of the full Board of Directors on June 15, 2021, the Management Agreement was unanimously continued for a term ending June 30, 2022 by the Fund’s Board of Directors, including the Independent Directors. The Independent Directors were represented by independent counsel who assisted them in their deliberations during the meetings and executive session.

In considering whether to continue the Management Agreement, the Board of Directors reviewed materials provided by an independent data provider, which included, among other items, fee, expense and performance information compared to peer funds (the Peer Funds and, collectively with the Fund, the Peer Group) and performance comparisons to a larger category universe; summary information prepared by the Fund’s investment manager (the Investment Manager); and a memorandum from counsel to the Independent Directors outlining the legal duties of the Board of Directors. The Board of Directors also spoke directly with representatives of the independent data provider and met with investment management personnel. In addition, the Board of Directors considered information provided from time to time by the Investment Manager throughout the year at meetings of the Board of Directors, including presentations by portfolio managers relating to the investment performance of the Fund and the investment strategies used in pursuing the Fund’s objective. The Board of Directors also considered information provided in response to a request for information submitted by counsel to the Independent Directors, as well as information provided in response to a supplemental request. Additionally, the Independent Directors noted that in connection with their considerations, that they had received information from the Investment Manager about, and discussed with the Investment Manager, the operations of its business continuity plan and related matters and the operations of third party service providers during the COVID-19 pandemic. In particular, the Board of Directors considered the following:

(i) The nature, extent and quality of services to be provided by the Investment Manager: The Board of Directors reviewed the services that the Investment Manager provides to the Fund, including, but not limited to, making the day-to-day investment decisions for the Fund, placing orders for the investment and reinvestment of the Fund’s assets, furnishing information to the Board of Directors of the Fund regarding the Fund’s portfolio, providing individuals to serve as Fund officers, and generally managing the Fund’s investments in accordance with the stated policies of the Fund. The Board of Directors also discussed with officers and portfolio managers of the Fund the types of transactions conducted on behalf of the Fund. Additionally, the Board of Directors took into account the services provided by the Investment Manager to its other funds and accounts, including those that have investment objectives and strategies similar to those of the Fund. The Board of Directors also considered the education, background and experience of the Investment Manager’s personnel, particularly noting the potential

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benefit that the portfolio managers’ work experience and favorable reputation can have on the Fund. The Board of Directors further noted the Investment Manager’s ability to attract qualified and experienced personnel. The Board of Directors also considered the administrative services provided by the Investment Manager, including compliance and accounting services. After consideration of the above factors, among others, the Board of Directors concluded that the nature, extent and quality of services provided by the Investment Manager are satisfactory and appropriate.

(ii) Investment performance of the Fund and the Investment Manager: The Board of Directors considered the investment performance of the Fund compared to Peer Funds and compared to a relevant linked benchmark. The Board of Directors noted that the Fund outperformed the Peer Group medians for the one-, three-, five- and ten-year periods ended March 31, 2021, ranking in the first, first, second, and second quintiles, respectively. The Board of Directors noted that the Fund outperformed its linked benchmark for the one-, three-, five- and ten-year periods ended March 31, 2021. The Board of Directors engaged in discussions with the Investment Manager regarding the contributors to and detractors from the Fund’s performance during the period, including the relevant implications of the continuing COVID-19 pandemic. The Board of Directors also considered supplemental information provided by the Investment Manager, including a narrative summary of various factors affecting performance and the Investment Manager’s performance in managing similarly managed funds and accounts. The Board of Directors determined that Fund performance, in light of all the considerations noted above, supported the continuation of the Management Agreement.

(iii) Cost of the services to be provided and profits to be realized by the Investment Manager from the relationship with the Fund: The Board of Directors considered the management fee paid by the Fund as well as the Fund’s total expense ratio. As part of its analysis, the Board of Directors gave consideration to the fee and expense analyses provided by the independent data provider. The Board of Directors noted that the Fund’s actual management fee and total expense ratio were lower than the Peer Group medians, ranking in the third and second quintiles, respectively. The Board of Directors also considered the effect the unitary fee charged by the Investment Manager, which limits total expenses of the Fund, has on the Fund’s actual management fee and total expense rankings. In light of the considerations above, the Board of Directors concluded that the Fund’s current expense structure was satisfactory.

The Board of Directors also reviewed information regarding the profitability to the Investment Manager of its relationship with the Fund. The Board of Directors considered the level of the Investment Manager’s profits and whether the profits were reasonable for the Investment Manager. The Board of Directors took into consideration other benefits to be derived by the Investment Manager in connection with the Management Agreement, noting particularly the research and related services, within the meaning of Section 28(e) of the Securities Exchange Act of 1934, that the Investment Manager receives by allocating the Fund’s brokerage transactions. The Board of Directors further considered that the Investment Manager continues to reinvest profits back in the business, including upgrading and/or implementing new trading, compliance and accounting systems, and by adding investment personnel to the portfolio management teams. The Board of Directors concluded that the profits realized by the Investment Manager from its relationship with the Fund were reasonable and consistent with the Investment Manager’s fiduciary duties.

(iv) The extent to which economies of scale would be realized as the Fund grows and whether fee levels would reflect such economies of scale: The Board of Directors noted that the Investment Manager

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COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

pays most of the regular operating costs of the Fund and reimburses the Fund for certain expenses to the extent that total expenses exceed the management fee rate. The Board of Directors determined that there were not at this time significant economies of scale that were not being shared with shareholders. In considering economies of scale, the Board of Directors also noted, as discussed above in (iii), that the Investment Manager continues to reinvest profits back in the business.

(v) Comparison of services to be rendered and fees to be paid to those under other investment management contracts, such as contracts of the same and other investment advisors or other clients: As discussed above in (iii), the Board of Directors compared the fees paid under the Management Agreement to those under other investment management contracts of other investment advisors managing Peer Funds. The Board of Directors also compared the services rendered and fees paid under the Management Agreement to fees paid, including the ranges of such fees, under the Investment Manager’s other fund advisory agreements and advisory contracts with institutional and other clients with similar investment mandates, noting that the Investment Manager provides more services to the Fund than it does for institutional or subadvised accounts. The Board of Directors also considered the entrepreneurial risk and financial exposure assumed by the Investment Manager in developing and managing the Fund that the Investment Manager does not have with institutional and other clients and other differences in the management of registered investment companies and institutional accounts. The Board of Directors determined that on a comparative basis the fees under the Management Agreement were reasonable in relation to the services provided.

No single factor was cited as determinative to the decision of the Board of Directors, and each Director may have assigned different weights to the various factors. Rather, after weighing all of the considerations and conclusions discussed above, the Board of Directors, including the Independent Directors, unanimously approved the continuation of the Management Agreement.

28

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

LIQUIDITY RISK MANAGEMENT PROGRAM

Pursuant to Rule 22e-4 under the Investment Company Act of 1940 (the Liquidity Rule), the Fund has adopted and implemented a liquidity risk management program (the Program). The Liquidity Rule requires an open-end investment company to adopt a program that is reasonably designed to assess and manage its liquidity risk, which is the risk that an open-end investment company could not meet redemption requests without significant dilution of remaining investors’ interests in the open-end investment company. The Board has designated Cohen & Steers Capital Management, Inc. (the Investment Manager) as the administrator of the Program. The Investment Manager has delegated this responsibility to the Liquidity Risk Management Committee (the LRM Committee), which is comprised of representatives from various departments within the Investment Manager. The Program includes policies and procedures reasonably designed to: (1) assess, manage, and periodically review the Fund’s liquidity risk; (2) classify the Fund’s portfolio investments as highly liquid, moderately liquid, less liquid, or illiquid; (3) determine a highly liquid investment minimum (HLIM) for the Fund or determine that one is not required; (4) limit the Fund’s illiquid investments to no more than 15% of its net assets; and (5) establish how and when the Fund will engage in in-kind redemptions.

The Board met on June 15, 2021 (the Meeting) to review the Program. At the Meeting, the LRM Committee provided the Board with a report that addressed the operation of the Program, including its implementation and effectiveness in assessing and managing the Fund’s liquidity risk (the Report). The Report covered the period from April 1, 2020 through March 31, 2021 (the Reporting Period).

The Report described the LRM Committee’s role in administering the Program, which complied with the Liquidity Rule requirements for assessing, managing and reviewing the Fund’s liquidity risk through the LRM Committee’s daily monitoring and quarterly analysis of liquidity parameters which include historical net redemption activity and consideration of the Fund’s shareholder ownership concentration, as applicable. The Report noted that the Fund’s investments are categorized into one of four liquidity buckets: highly liquid, moderately liquid, less liquid and illiquid. Liquidity classifications take into account a variety of market, trading, and investment factors, including the Fund’s reasonably anticipated trade size. The Investment Manager has engaged a third-party vendor to assist with the classification of portfolio investments. The Report also described the LRM Committee’s determination that the Fund is a primarily highly liquid fund under the Liquidity Rule.

The Report noted that there were no liquidity events during the Reporting Period that materially impacted the Fund’s ability to timely meet redemptions without significantly diluting remaining shareholders’ interests. The Report concluded that the Program is operating as intended, effective in implementing the requirements of the Liquidity Rule and reasonably designed to assess and manage the Fund’s liquidity risk.

There can be no assurance that the Program will achieve its objectives in the future. Please refer to the Fund’s prospectus for more information regarding the Fund’s exposure to liquidity risk and other principal risks to which an investment in the Fund may be subject.

29

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

Cohen & Steers Privacy Policy

Facts	What Does Cohen & Steers Do With Your Personal Information?
Why?	Financial companies choose how they share your personal information. Federal law gives consumers the right to limit some but not all sharing. Federal law also requires us to tell you how we collect, share, and protect your personal information. Please read this notice carefully to understand what we do.
What?	The types of personal information we collect and share depend on the product or service you have with us. This information can include: • Social Security number and account balances • Transaction history and account transactions • Purchase history and wire transfer instructions
How?	All financial companies need to share customers’ personal information to run their everyday business. In the section below, we list the reasons financial companies can share their customers’ personal information; the reasons Cohen & Steers chooses to share; and whether you can limit this sharing.

Reasons we can share your personal information	Does Cohen & Steers share?	Can you limit this sharing?
For our everyday business purposes— such as to process your transactions, maintain your account(s), respond to court orders and legal investigations, or reports to credit bureaus	Yes	No
For our marketing purposes— to offer our products and services to you	Yes	No
For joint marketing with other financial companies—	No	We don’t share
For our affiliates’ everyday business purposes— information about your transactions and experiences	No	We don’t share
For our affiliates’ everyday business purposes— information about your creditworthiness	No	We don’t share
For our affiliates to market to you—	No	We don’t share
For non-affiliates to market to you—	No	We don’t share
Questions?    Call 800.330.7348

30

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

Cohen & Steers Privacy Policy—(Continued)

Who we are
Who is providing this notice?	Cohen & Steers Capital Management, Inc., Cohen & Steers Asia Limited, Cohen & Steers Japan Limited, Cohen & Steers UK Limited, Cohen & Steers Ireland Limited, Cohen & Steers Securities, LLC, Cohen & Steers Private Funds and Cohen & Steers Open and Closed-End Funds (collectively, Cohen & Steers).
What we do
How does Cohen & Steers protect my personal information?	To protect your personal information from unauthorized access and use, we use security measures that comply with federal law. These measures include computer safeguards and secured files and buildings. We restrict access to your information to those employees who need it to perform their jobs, and also require companies that provide services on our behalf to protect your information.
How does Cohen & Steers collect my personal information?	We collect your personal information, for example, when you: • Open an account or buy securities from us • Provide account information or give us your contact information • Make deposits or withdrawals from your account We also collect your personal information from other companies.
Why can’t I limit all sharing?	Federal law gives you the right to limit only: • sharing for affiliates’ everyday business purposes—information about your creditworthiness • affiliates from using your information to market to you • sharing for non-affiliates to market to you State law and individual companies may give you additional rights to limit sharing.
Definitions
Affiliates	Companies related by common ownership or control. They can be financial and nonfinancial companies. • Cohen & Steers does not share with affiliates.
Non-affiliates	Companies not related by common ownership or control. They can be financial and nonfinancial companies. • Cohen & Steers does not share with non-affiliates.
Joint marketing	A formal agreement between non-affiliated financial companies that together market financial products or services to you. • Cohen & Steers does not jointly market.

31

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

Cohen & Steers Open-End Mutual Funds

COHEN & STEERS REALTY SHARES

• Designed for investors seeking total return, investing primarily in U.S. real estate securities

• Symbols: CSJAX, CSJCX, CSJIX, CSRSX, CSJRX, CSJZX

COHEN & STEERS REAL ESTATE SECURITIES FUND

• Designed for investors seeking total return, investing primarily in U.S. real estate securities

• Symbols: CSEIX, CSCIX, CREFX, CSDIX, CIRRX, CSZIX

COHEN & STEERS INSTITUTIONAL REALTY SHARES

• Designed for institutional investors seeking total return, investing primarily in U.S. real estate securities

• Symbol: CSRIX

COHEN & STEERS GLOBAL REALTY SHARES

• Designed for investors seeking total return, investing primarily in global real estate equity securities

• Symbols: CSFAX, CSFCX, CSSPX, GRSRX, CSFZX

COHEN & STEERS INTERNATIONAL REALTY FUND

• Designed for investors seeking total return, investing primarily in international (non-U.S.) real estate securities

• Symbols: IRFAX, IRFCX, IRFIX, IRFRX, IRFZX

COHEN & STEERS REAL ASSETS FUND

• Designed for investors seeking total return and the maximization of real returns during inflationary environments by investing primarily in real assets

• Symbols: RAPAX, RAPCX, RAPIX, RAPRX, RAPZX

COHEN & STEERS PREFERRED SECURITIES AND INCOME FUND

• Designed for investors seeking total return (high current income and capital appreciation), investing primarily in preferred and debt securities issued by U.S. and non-U.S. companies

• Symbols: CPXAX, CPXCX, CPXFX, CPXIX, CPRRX, CPXZX

COHEN & STEERS LOW DURATION PREFERRED AND INCOME FUND

• Designed for investors seeking high current income and capital preservation by investing in low-duration preferred and other income securities issued by U.S. and non-U.S. companies

• Symbols: LPXAX, LPXCX, LPXFX, LPXIX, LPXRX, LPXZX

COHEN & STEERS MLP & ENERGY OPPORTUNITY FUND

• Designed for investors seeking total return, investing primarily in midstream energy master limited partnership (MLP) units and related stocks

• Symbols: MLOAX, MLOCX, MLOIX, MLORX, MLOZX

COHEN & STEERS GLOBAL INFRASTRUCTURE FUND

• Designed for investors seeking total return, investing primarily in global infrastructure securities

• Symbols: CSUAX, CSUCX, CSUIX, CSURX, CSUZX

COHEN & STEERS ALTERNATIVE INCOME FUND

• Designed for investors seeking high current income and capital appreciation, investing in equity, preferred and debt securities, focused on real assets and alternative income strategies

• Symbols: DVFAX, DVFCX, DVFIX, DVFRX, DVFZX

Distributed by Cohen & Steers Securities, LLC.

Please consider the investment objectives, risks, charges and expenses of any Cohen & Steers U.S. registered open-end fund carefully before investing. A summary prospectus and prospectus containing this and other information can be obtained by calling 800-330-7348 or by visiting cohenandsteers.com. Please read the summary prospectus and prospectus carefully before investing.

32

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

OFFICERS AND DIRECTORS

Robert H. Steers

Director and Chairman

Joseph M. Harvey

Director and Vice President

Michael G. Clark

Director

George Grossman

Director

Dean A. Junkans

Director

Gerald J. Maginnis

Director

Jane F. Magpiong

Director

Daphne L. Richards

Director

Ramona Rogers-Windsor

Director

C. Edward Ward, Jr.

Director

Adam M. Derechin

President and Chief Executive Officer

James Giallanza

Chief Financial Officer

Dana A. DeVivo

Secretary and Chief Legal Officer

Albert Laskaj

Treasurer

Stephen Murphy

Chief Compliance Officer and Vice President

Jon Cheigh

Vice President

Jason A. Yablon

Vice President

Mathew Kirschner

Vice President

KEY INFORMATION

Investment Manager and Administrator

Cohen & Steers Capital Management, Inc

280 Park Avenue

New York, NY 10017

(212) 832-3232

Co-administrator and Custodian

State Street Bank and Trust Company

One Lincoln Street

Boston, MA 02111

Transfer Agent

DST Asset Manager Solutions, Inc.

P.O. Box 219953

Kansas City, MO 64121-9953

(800) 437-9912

Legal Counsel

Ropes & Gray LLP

1211 Avenue of the Americas

New York, NY 10036

Distributor

Cohen & Steers Securities, LLC

280 Park Avenue

New York, NY 10017

NASDAQ Symbol: CSRIX

Website: cohenandsteers.com

This report is authorized for delivery only to shareholders of Cohen & Steers Institutional Realty Shares, Inc. unless accompanied or preceded by the delivery of a currently effective prospectus setting forth details of the Fund. Performance data quoted represent past performance. Past performance is no guarantee of future results and your investment may be worth more or less at the time you sell your shares.

33

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Cohen & Steers

Institutional

Realty Shares

Semiannual Report June 30, 2021

As permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund’s annual and semi-annual shareholder reports are no longer sent by mail, unless you specifically requested paper copies of the reports. Instead, the reports are made available on the Fund’s website at www.cohenandsteers.com, and you will be notified by mail each time a report is posted and provided with a website link to access the report.

If you have already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from a Fund electronically anytime by contacting your financial intermediary or, if you are a direct investor, by signing up at www.cohenandsteers.com.

You may elect to receive all future reports in paper, free of charge, at any time. If you invest through a financial intermediary, you can contact your financial intermediary or, if you are a direct investor, you can call (800) 330-7348 to let the Fund know you wish to continue receiving paper copies of your shareholder reports. Your election to receive reports in paper will apply to all Funds held in your account if you invest through your financial intermediary or all Funds held within the fund complex if you invest directly with the Fund.

CSRIXSAR

Item 2. Code of Ethics.

Not applicable.

Item 3. Audit Committee Financial Expert.

Not applicable.

Item 4. Principal Accountant Fees and Services.

Not applicable.

Item 5. Audit Committee of Listed Registrants.

Not applicable.

Item 6. Schedule of Investments.

Included in Item 1 above.

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

Not applicable.

Item 8. Portfolio Managers of Closed-End Investment Companies.

Not applicable.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not applicable.

Item 10. Submission of Matters to a Vote of Security Holders.

None.

Item 11. Controls and Procedures.

(a) The registrant’s principal executive officer and principal financial officer have concluded that the registrant’s disclosure controls and procedures are reasonably designed to ensure that information required to be disclosed by the registrant in this Form N-CSR was recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms, based upon such officers’ evaluation of these controls and procedures as of a date within 90 days of the filing date of this report.

(b) There were no changes in the registrant’s internal control over financial reporting that occurred during the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies.

Not applicable.

Item 13. Exhibits.

(a)(1) Not applicable.

(a)(2) Certifications of principal executive officer and principal financial officer as required by Rule 30a-2(a) under the Investment Company Act of 1940.

(a)(3) Not applicable.

(a)(4) Not applicable.

(b) Certifications of principal executive officer and principal financial officer as required by Rule 30a- 2(b) under the Investment Company Act of 1940.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

COHEN & STEERS INSTITUTIONAL REALTY SHARES, INC.

By:	/s/ Adam M. Derechin
	Name:   Adam M. Derechin Title:    Principal Executive Officer          (President and Chief Executive Officer)
Date: August 27, 2021

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By:	/s/ Adam M. Derechin
	Name:   Adam M. Derechin Title:    Principal Executive Officer          (President and Chief Executive Officer)
By:	/s/ James Giallanza
	Name:   James Giallanza Title:    Principal Financial Officer          (Chief Financial Officer)
Date: August 27, 2021

EX-99.CERT

EX-99.CERT

EXHIBIT 13 (a)(2)

RULE 30a-2(a) CERTIFICATIONS

I, Adam M. Derechin, certify that:

1. I have reviewed this report on Form N-CSR of Cohen & Steers Institutional Realty Shares, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: August 27, 2021

/s/ Adam M. Derechin

Adam M. Derechin

Principal Executive Officer

(President and Chief Executive Officer)

EXHIBIT 13 (a)(2)

RULE 30a-2(a) CERTIFICATIONS

I, James Giallanza, certify that:

1. I have reviewed this report on Form N-CSR of Cohen & Steers Institutional Realty Shares, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: August 27, 2021

/s/ James Giallanza

James Giallanza

Principal Financial Officer

(Chief Financial Officer)

EX-99.906CT

EX-99.906CERT

EXHIBIT 13 (b)

RULE 30a-2(b) CERTIFICATIONS

In connection with the Report of Cohen & Steers Institutional Realty Shares, Inc. (the “Company”) on Form N-CSR as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Adam M. Derechin, Principal Executive Officer of the Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as applicable; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Adam M. Derechin

Adam M. Derechin

Principal Executive Officer

(President and Chief Executive Officer)

Date: August 27, 2021

EXHIBIT 13 (b)

RULE 30a-2(b) CERTIFICATIONS

In connection with the Report of Cohen & Steers Institutional Realty Shares, Inc. (the “Company”) on Form N-CSR as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, James Giallanza, Principal Financial Officer of the Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as applicable; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ James Giallanza

James Giallanza

Principal Financial Officer

(Chief Financial Officer)

Date: August 27, 2021