Mutual Of America Investment N-CSRSCertified semi-annual shareholder report (management investment company)

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 811-05084

Mutual of America Investment Corporation

(Exact name of registrant as specified in charter)

320 Park Avenue, New York, N.Y. 10022

(Address of principal executive offices) (Zip code)

James J. Roth

Chairman of the Board, President and Chief Executive Officer

Mutual of America Investment Corporation

320 Park Avenue

New York, NY 10022

(Name and address of agent for service)

Registrant’s telephone number, including area code: (212) 224-1600

Date of fiscal year end: December 31

Date of reporting period: June 30, 2021

The Semi-Annual Report to Shareholders follows:

JUNE 30, 2021

Semi-Annual Reports of Mutual of America Investment Corporation Funds

This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.

CONTENTS

MUTUALOF AMERICA INVESTMENT CORPORATION

We are pleased to present the Mutual of America Investment Corporation (the “Investment Company”) Semi-Annual Report. This Report includes important information regarding the performance and financial position of the Investment Company’s funds for the six months ended June 30, 2021.

Vaccines and Jobs Drive Optimism

U.S. investors have been extremely optimistic about the financial markets during the first six months of 2021. Much of the strength in the financial markets is due to the approval and rollout of several COVID-19 vaccines. Those vaccines have allowed Americans to resume their lives and return to relative normalcy as restrictions on most businesses throughout the country have been lifted or relaxed. With more than 50% of the U.S. population fully vaccinated, it will be difficult for federal, state or local governments to reimpose broad lockdowns, as these would likely have a meaningful negative economic impact.

In addition, during the first half of this year, the consumer balance sheet has proven to be quite strong. Personal saving peaked this year in March at 26.9% which is significantly higher than pre-pandemic levels in March 2019 of 8.0%. While 6.2 million people reported in June that they were unable to work because their employer closed or lost business due to the pandemic, this is down from 7.9 million in May and is a vast improvement from the double-digit levels experienced last year. Given the general financial health of the consumer and the improving employment situation, the economy is likely to be robust for the foreseeable future.

Market Snapshot

With the backdrop of a strong U.S. economy, equity markets in the second quarter of 2021 added to the gains achieved in the first quarter. Overall, the S&P 500^® Index reached all-time highs on 34 occasions in the first half of 2021. The best returns for the second quarter and year to date were in the cyclical, sensitive sectors, such as energy and financials. However, all domestic and international equities posted mid-to-high single-digit returns for the second quarter alone and high single- to double-digit returns for the year to date. Through June 30, 2021, U.S. equity markets outperformed international equity markets, reflecting the earlier vaccination adoption success in the U.S. It is also worth noting that U.S. small-cap stocks were the best-performing segment of the equity market during the first half of 2021, given their high operating leverage to the reopening of the economy.

In the fixed income markets, the 10-year U.S. Treasury bond rose to 1.76% at the start of the second quarter, as investors worried that strong consumer demand and ample monetary and fiscal liquidity would lead to higher levels of inflation. Once again, the U.S. Federal Reserve (Fed) offered reassurance that price increases would only be temporary and that the Fed would be ready to reduce bond purchases if higher levels of inflation were to evolve. By the end of the quarter, the fixed income markets settled down, and the 10-year Treasury yield had retreated to 1.47%.

Outlook

As this summer has progressed, the Delta variant of the coronavirus has proven quite transmissible, especially among non-vaccinated individuals, leading to a spike in infections in pockets of the U.S. However, as long as the Delta variant can be contained, the economy should remain on strong footing given the strength in consumer spending, declining unemployment levels and moderate levels of inflation. If that is the case, the economic expansion should continue throughout the balance of the year, which would likely continue to boost the already strong equity markets.

The total return performance (net of investment management and other operating expenses) for each of the Investment Company Funds is reflected below:

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For variable annuity owners or participants in a group variable annuity, the above performance figures do not reflect the deduction of respective Separate Account fees and expenses imposed by Mutual of America Life Insurance Company. All Fund performances presented throughout this report are historical, reflect the full reinvestment of dividends paid, and should not be considered indicative of future results.

The pages that immediately follow include brief discussions of each Fund’s performance for the six months ended June 30, 2021, compared to its relevant index.

Following the discussions are the graphical representations of the asset allocations of each Fund and an illustration of each Fund’s operating expenses. The portfolios of each Fund and financial statements are presented in the pages that follow.

Thank you for your continued investment in our Funds.

Sincerely,

James J. Roth

Chairman of the Board,

President and Chief Executive Officer

Mutual of America Investment Corporation

The views expressed in this Semi-Annual Report are subject to change at any time based on market and other conditions and should not be construed as a recommendation. This Report contains forward-looking statements which speak only as of the date they were made and involve a number of risks and uncertainties that could cause actual results to differ materially from those expressed herein. Readers are cautioned not to place undue reliance on our forward-looking statements, as we assume no obligation to update these forward-looking statements. Readers assume any and all responsibility for any investment decision made as a result of the views expressed herein.

S&P^® and S&P 500^® are trademarks of Standard & Poor’s Financial Services LLC.

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EQUITY INDEX FUND (Unaudited)

The Equity Index Fund’s objective is to replicate the performance of the S&P 500^® Index (S&P 500), which consists of 500 stocks chosen by Standard & Poor’s for market size, liquidity and industry group representation. The S&P 500 is a market-weighted index of 500 stocks traded on the New York Stock Exchange, American Stock Exchange and NASDAQ, with each stock’s weight in the index proportionate to its market value. The weightings make each company’s influence on the S&P 500’s performance directly proportional to that company’s market value.

The Equity Index Fund’s performance for the six months ended June 30, 2021, was 15.24% before expenses and 15.16% after expenses. The benchmark returned 15.25%. Note that the Equity Index Fund’s performance includes expenses, such as transaction costs and management fees, which are not applicable to the benchmark.

ALL AMERICA FUND (Unaudited)

The investment objective of the All America Fund is to outperform the S&P 500^® Index (S&P 500). The All America Fund is approximately 60% passively invested in the 500 stocks that comprise the S&P 500, with the remaining 40% actively managed, comprised of 20% mid-cap capitalization stocks and 20% small cap stocks, thus providing exposure to all levels of market capitalization among domestic stocks.

For the six months ended June 30, 2021, the S&P 500 of large capitalization stocks increased by 15.25% on a total return basis, while the Russell^® Midcap Core Index was up 16.25% and the Russell Midcap^® Value Index was up 19.45%. The Russell 2000^® Growth Index increased 8.98% and the Russell 2000^® Value Index increased 26.69%.

The All America Fund’s return for the six months ended June 30, 2021, before expenses was 16.77% and 16.46% after expenses versus the benchmark return of 15.25%. The underperformance of the Fund versus the S&P 500 during the year was due to the underperformance of the small and mid capitalization segments of the Fund as compared to the large capitalization benchmark.

SMALL CAP VALUE FUND (Unaudited)

The investment objective of the Small Cap Value Fund is capital appreciation. The Small Cap Value Fund generally invests in companies that are below $3 billion in market capitalization and have lower price-to-book characteristics than the overall market.

For the six months ended June 30, 2021, the Small Cap Value Fund returned 26.06% before expenses and 25.54% after expenses versus a 26.69% return for the Russell 2000^® Value Index. Within the benchmark the best performing sectors were Energy and Retail, while the worst performing sectors were Utilities and Consumer Staples.

Stock selection was the primary driver of negative performance versus the benchmark. Sectors contributing to Fund performance included Health Care and Technology while sectors detracting from Fund performance included Retail and Real Estate.

SMALL CAP GROWTH FUND (Unaudited)

The investment objective of the Small Cap Growth Fund is capital appreciation. The Small Cap Growth Fund invests in growth stocks within the small capitalization marketplace. The Fund returned 10.43% before expenses and 9.98% after expenses during the six months ended June 30, 2021. The Fund’s benchmark, the Russell 2000^® Growth Index, returned 8.98% for the comparable period.

The majority of our outperformance came from the Consumer Discretionary sector which increased 38% for the first six months of the year compared to this sector in the Russell 2000^® Growth Index which increased approximately 25%. The Consumer Discretionary sector was one of the key areas benefitting from the re-opening of the economy.    After Energy, this sector was the second best performing sector in our benchmark.

We struggled in the Industrial sector given the well-above average expected Gross Domestic Product (GDP) growth for 2021. Health Care was also difficult given poor stock selection in the managed care area of healthcare services.

Nonetheless, the portfolio produced a near double digit return for the first six months of the year after a stellar 2020.

SMALL CAP EQUITY INDEX FUND (Unaudited)

The Small Cap Equity Index Fund invests in the 600 stocks that comprise the S&P SmallCap 600^® Index (S&P SmallCap 600). The S&P SmallCap 600 is a market-weighted index of 600 stocks traded on the New York Stock Exchange, American Stock Exchange and NASDAQ. The weightings make each company’s influence on the S&P SmallCap 600’s performance directly proportional to that company’s market value.

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The Small Cap Equity Index Fund’s return for six months ended June 30, 2021, was 23.52% before expenses and 23.43% after expenses. The return of the S&P SmallCap 600 was 23.56%. Note that the performance of the Small Cap Equity Index Fund includes expenses, such as transaction costs and management fees, which are not applicable to the benchmark.

MID CAP VALUE FUND (Unaudited)

The investment objective of the Mid Cap Value Fund is to outperform the Russell Midcap^® Value Index. The Mid Cap Value Fund generally invests in companies that are between $1 billion and $20 billion in market capitalization and have lower price-to-book characteristics.

For the six months ended June 30, 2021, the Mid Cap Value Fund returned 22.40% before expenses and 22.00% after expenses versus a 19.45% return for the Russell Midcap^® Value Index. Within the benchmark the best performing sectors were Energy and Financials, while the worst performing sectors were Utilities and Consumer Staples.

Stock selection was the primary driver of positive performance versus the benchmark. Sectors contributing to Fund performance included Technology and Health Care while sectors detracting from Fund performance included Basic Materials and Real Estate.

MID-CAP EQUITY INDEX FUND (Unaudited)

The Mid-Cap Equity Index Fund invests in the 400 stocks that comprise the S&P MidCap 400^® Index (S&P MidCap 400). The S&P MidCap 400 is a market-weighted index of 400 stocks traded on the New York Stock Exchange, American Stock Exchange and NASDAQ. The weightings make each company’s influence on the S&P MidCap 400’s performance directly proportional to that company’s market value. The companies included in the S&P MidCap 400 tend to be typical of this asset class, the medium-capitalized sector of the U.S. securities market.

The Mid-Cap Equity Index Fund’s performance for the six months ended June 30, 2021, was 17.64% before expenses and 17.56% after expenses. The return of the S&P MidCap 400 was 17.59%. Note that the performance of the Mid-Cap Equity Index Fund includes expenses, such as transaction costs and management fees, which are not applicable to the benchmark.

COMPOSITE FUND (Unaudited)

The Composite Fund seeks capital appreciation and current income by investing in a diversified portfolio of common stocks, debt securities and money market instruments.

The primary investment objective of the fixed income portion of the fund is to provide a high level of current income, consistent with capital preservation, while minimizing volatility. It does this by investing primarily in investment grade publicly traded debt securities. The securities held include corporate, U.S. agency and mortgage-backed securities, all of which normally yield more than U.S. Treasury issues.

For the six months ended June 30, 2021, the fixed income portion of the Fund had a total return of -1.53% before expenses. The Bloomberg Barclays U.S. Aggregate Index returned -1.60% for the six months ended June 30, 2021.

The primary objective of the equity portion of the Composite Fund is to provide exposure to a diversified portfolio of primarily large capitalization, domestic equity securities that have the potential to outperform their peer group over the medium to long term. The portfolio has a focus on dividend income and aims to continually earn a dividend yield that is higher than that of its benchmark without taking significant over or under weights in any sector.

For the six months ended June 30, 2021, the equity portion of the Fund had a total return of 17.63% (before expenses), outperforming the S&P 500^® Index (S&P 500) which increased 15.25%.

The Fund’s aggregate performance for the six months ended June 30, 2021 was 9.66% before expenses and 9.38% after expenses, versus a 8.35% return in the weighted benchmark.

INTERNATIONAL FUND (Unaudited)

The International Fund seeks capital appreciation by investing, directly or indirectly, mainly in exchange traded funds that invest in stocks of large and mid-cap companies in developed market countries located outside of the United States and Canada that are reflected or contained in the Morgan Stanley Capital International, Inc. Europe, Australasia and Far East^® Index (MSCI EAFE^® Index). Currently the International Fund is invested mainly in exchange traded funds that reflect, replicate or follow the country weightings of the MSCI EAFE^® Index. The Fund also has invested a small percentage of assets in exchange traded funds that provide exposure to emerging markets and to companies with small market capitalizations in developed market countries.

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For the six months ended June 30, 2021, the International Fund returned 9.19% before expenses and 9.12% after expenses. The return of the MSCI EAFE benchmark was 8.83%. The fund’s benchmark closes earlier in the day than the actual market for the fund’s investments. This time lag can result in both positive and negative performance differences.

CATHOLIC VALUES INDEX FUND (Unaudited)

The Catholic Values Index Fund’s objective is to replicate the performance of the S&P 500^® Catholic Values Index (Catholic Values Index). The Catholic Values Index is designed to provide exposure to U.S. large capitalization stocks included in the S&P 500^® Index (S&P 500) while maintaining alignment with the moral and social teachings of the Catholic Church. The Catholic Values Index is based on the S&P 500, and generally comprises approximately 500 or less U.S. listed common stocks. All index constituents are members of the S&P 500 and follow the eligibility criteria for that index. From this starting universe, constituents are screened to exclude companies involved in activities which are perceived to be inconsistent with Catholic values as outlined in the Socially Responsible Investment Guidelines of the United States Conference of Catholic Bishops, currently including the protection of human life, promotion of human dignity, reducing arms production, affordable housing and banking, protection of the environment and encouraging corporate responsibility. The Catholic Values Index then reweights the remaining constituents so that the Catholic Values Index’s sector exposures approximate the sector exposures on the S&P 500.

The Catholic Values Index Fund’s performance for the six months ended June 30, 2021, was 16.15% before expenses and 16.02% after expenses. The benchmark returned 16.19%. Note that the Catholic Values Index Fund’s performance includes expenses, such as transaction costs and management fees, which are not applicable to the benchmark.

RETIREMENT INCOME FUND (Unaudited)

The objective of the Retirement Income Fund is current income consistent with the preservation of capital and, to a lesser extent, capital appreciation. The Retirement Income Fund invests primarily in the fixed-income funds of the Investment Company and also invests in two equity funds of the Investment Company. The Fund’s current target allocation is approximately 75% of net assets in fixed-income funds (approximately 35% in the Bond, 25% in the Mid-Term Bond Funds and 15% in the Money Market Fund) and approximately 25% of net assets in equity funds (20% in the Equity Index Fund and 5% in the Mid-Cap Equity Index Fund) (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the Retirement Income Fund is compared to the Bloomberg Barclays U.S. Aggregate Bond Index (60% weighting), the FTSE 3-Month Treasury Bill Index (15% weighting) and the S&P 500^® Index (25% weighting). For the six months ended June 30, 2021, the Fund returned 3.04% before expenses and 2.98% after expenses, versus a 2.68% return in the weighted benchmark.

2015 RETIREMENT FUND (Unaudited)

The objective of the 2015 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a retirement in 2015. The 2015 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 67% of net assets in fixed-income funds (37% in the Bond Fund, 20% in the Mid-Term Bond Fund and 10% in the Money Market Fund) and approximately 33% of net assets in equity funds (approximately 22% in the Equity Index Fund, 6% in the Mid-Cap Equity Index Fund and 5% in the International Fund) (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2015 Retirement Fund is compared to the Bloomberg Barclays U.S. Aggregate Bond Index (57% weighting), the FTSE 3-Month Treasury Bill Index (10% weighting) and the S&P 500^® Index (33% weighting). For the six months ended June 30, 2021, the Fund returned 4.68% before expenses and 4.61% after expenses, versus a 3.92% return in the weighted benchmark.

2020 RETIREMENT FUND (Unaudited)

The objective of the 2020 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a retirement in 2020. The 2020 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 57% of net assets in fixed-income funds (37% in the Bond Fund, 15% in the Mid-Term Bond Fund and 5% in the Money Market Fund) and approximately 43% of net assets in equity funds (approximately 23% in the Equity Index Fund, 8% in the Mid-Cap Equity Index Fund, 8% in the

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International Fund and 2% each in the Small Cap Growth and Small Cap Value Funds) (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2020 Retirement Fund is compared to the Bloomberg Barclays U.S. Aggregate Bond Index (52% weighting), the FTSE 3-Month Treasury Bill Index (5% weighting) and the S&P 500^® Index (43% weighting). For the six months ended June 30, 2021, the Fund returned 6.05% before expenses and 6.01% after expenses, versus a 5.50% return in the weighted benchmark.

2025 RETIREMENT FUND (Unaudited)

The objective of the 2025 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2025. The 2025 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 53% of net assets in equity funds (approximately 27% in the Equity Index Fund, 12% in the Mid-Cap Equity Index Fund, 10% in the International Fund and 2% each in the Small Cap Growth and Small Cap Value Funds) and approximately 47% of net assets in fixed-income funds (32% in the Bond Fund, 10% in the Mid-Term Bond Fund and 5% in the Money Market Fund) (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2025 Retirement Fund is compared to the S&P 500^® Index (53% weighting), the Bloomberg Barclays U.S. Aggregate Bond Index (42% weighting) and the FTSE 3-Month Treasury Bill Index (5% weighting). For the six months ended June 30, 2021, the Fund returned 7.57% before expenses and 7.54% after expenses, versus a 7.18% return in the weighted benchmark.

2030 RETIREMENT FUND (Unaudited)

The objective of the 2030 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2030. The 2030 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 65% of net assets in equity funds (approximately 33% in the Equity Index Fund, 15% in the Mid-Cap Equity Index Fund, 12% in the International Fund, 2% each in the Small Cap Growth and Small Cap Value Funds and 1% in the Small Cap Equity Index Fund) and approximately 35% of net assets in fixed-income funds (25% in the Bond Fund, 5% in the Mid-Term Bond Fund and 5% in the Money Market Fund) (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2030 Retirement Fund is compared to the S&P 500^® Index (65% weighting), the Bloomberg Barclays U.S. Aggregate Bond Index (30% weighting) and the FTSE 3-Month Treasury Bill Index (5% weighting). For the six months ended June 30, 2021, the Fund returned 9.75% before expenses and 9.72% after expenses, versus a 9.22% return in the weighted benchmark.

2035 RETIREMENT FUND (Unaudited)

The objective of the 2035 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2035. The 2035 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 75% of net assets in equity funds (approximately 37% in the Equity Index Fund, 16% in the Mid-Cap Equity Index Fund, 15% in the International Fund, 3% each in the Small Cap Growth and Small Cap Value Funds and 1% in the Small-Cap Equity Index Fund) and approximately 25% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2035 Retirement Fund is compared to the S&P 500^® Index (75% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (25% weighting). For the six months ended June 30, 2021, the Fund returned 11.51% before expenses and 11.48% after expenses, versus a 10.86% return in the weighted benchmark.

2040 RETIREMENT FUND (Unaudited)

The objective of the 2040 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2040. The 2040 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 83% of net assets in equity funds (approximately 41% in the Equity Index Fund, 17% in the Mid-Cap Equity Index Fund, 17% in the International Fund, 3% each in the Small Cap Growth and Small Cap Value Funds and 2% in the Small-Cap Equity Index Fund) and approximately 17% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

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Performance for the 2040 Retirement Fund is compared to the S&P 500^® Index (83% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (17% weighting). For the six months ended June 30, 2021, the Fund returned 12.88% before expenses and 12.85% after expenses, versus a 12.25% return in the weighted benchmark.

2045 RETIREMENT FUND (Unaudited)

The objective of the 2045 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2045. The 2045 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 86% of net assets in equity funds (approximately 42% in the Equity Index Fund, 17% in the Mid-Cap Equity Index Fund, 18% in the International Fund, 4% each in the Small Cap Growth and Small Cap Value Funds and 1% in the Small-Cap Equity Index Fund) and approximately 14% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2045 Retirement Fund is compared to the S&P 500^® Index (86% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (14% weighting). For the six months ended June 30, 2021, the Fund returned 13.30% before expenses and 13.27% after expenses, versus a 12.78% return in the weighted benchmark.

2050 RETIREMENT FUND (Unaudited)

The objective of the 2050 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2050. The 2050 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 88% of net assets in equity funds (approximately 41% in the Equity Index Fund, 18% in the Mid-Cap Equity Index Fund, 19% in the International Fund, 4% each in the Small Cap Growth and Small Cap Value Funds and 2% in the Small-Cap Equity Index Fund) and approximately 12% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2050 Retirement Fund is compared to the S&P 500^® Index (88% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (12% weighting). For the year ended December 31, 2020, the Fund returned 13.66% before expenses and 13.61% after expenses, versus a 13.13% return in the weighted benchmark.

2055 RETIREMENT FUND (Unaudited)

The objective of the 2055 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2055. The 2055 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 90% of net assets in equity funds (approximately 40% in the Equity Index Fund, 19% in the Mid-Cap Equity Index Fund, 20% in the International Fund, 5% each in the Small Cap Growth and Small Cap Value Funds and 1% in the Small-Cap Equity Index Fund) and approximately 10% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2055 Retirement Fund is compared to the S&P 500^® Index (90% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (10% weighting). For the six months ended June 30, 2021, the Fund returned 13.94% before expenses and 13.88% after expenses, versus a 13.48% return in the weighted benchmark.

2060 RETIREMENT FUND (Unaudited)

The objective of the 2060 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2060. The 2060 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 92% of net assets in equity funds (approximately 39% in the Equity Index Fund, 20% in the Mid-Cap Equity Index Fund, 21% in the International Fund, 5% each in the Small Cap Growth and Small Cap Value Funds and 2% in the Small-Cap Equity Index Fund) and approximately 8% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2060 Retirement Fund is compared to the S&P 500^® Index (92% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (8% weighting). For the six months ended June 30, 2021, the Fund returned 14.43% before expenses and 14.41% after expenses, versus a 13.83% return in the weighted benchmark.

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2065 RETIREMENT FUND (Unaudited)

The objective of the 2065 Retirement Fund is current income and capital appreciation appropriate for the asset allocation associated with a target retirement in 2065. The 2065 Retirement Fund invests in funds of the Investment Company. The Fund’s current target allocation is approximately 94% of net assets in equity funds (approximately 38% in the Equity Index Fund, 21% in the Mid-Cap Equity Index Fund, 22% in the International Fund, 5% each in the Small Cap Growth and Small Cap Value Funds and 3% in the Small-Cap Equity Index Fund) and approximately 6% of net assets in the Bond Fund (See Note 1 in the Notes to Financial Statements for additional information on changes to Fund target allocations during 2021).

Performance for the 2065 Retirement Fund is compared to the S&P 500^® Index (94% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (6% weighting). For the six months ended June 30, 2021, the Fund returned 14.59% before expenses and 14.57% after expenses, versus a 14.19% return in the weighted benchmark.

CONSERVATIVE ALLOCATION FUND (Unaudited)

The objective of the Conservative Allocation Fund is current income and, to a lesser extent, capital appreciation. The Conservative Allocation Fund invests primarily in the fixed-income funds of the Investment Company and also invests in the equity funds of the Investment Company. The Conservative Allocation Fund’s target allocation is approximately 65% of net assets in fixed-income funds (approximately 30% in the Bond Fund and 35% in the Mid-Term Bond Fund) and approximately 35% of net assets in equity funds (approximately 25% in the Equity Index Fund, 5% in the Mid-Cap Equity Index Fund and 5% in the International Fund).

Performance for the Conservative Allocation Fund is compared to the Bloomberg Barclays U.S. Aggregate Bond Index (65% weighting) and the S&P 500^® Index (35% weighting). For the six months ended June 30, 2021, the Conservative Allocation Fund returned 4.59% before expenses and 4.56% after expenses, versus a 4.08% return in the weighted benchmark.

MODERATE ALLOCATION FUND (Unaudited)

The objective of the Moderate Allocation Fund is capital appreciation and current income. The Moderate Allocation Fund invests in the equity and fixed-income funds of the Investment Company. The Moderate Allocation Fund’s target allocation is approximately 60% of net assets in equity funds (approximately 35% of its net assets in the Equity Index Fund, 15% in the Mid-Cap Equity Index Fund and 10% in the International Fund) and approximately 40% of net assets in fixed-income funds (approximately 25% of its net assets in the Bond Fund and approximately 15% of its net assets in the Mid-Term Bond Fund).

Performance for the Moderate Allocation Fund is compared to the S&P 500^® Index (60% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (40% weighting). For the six months ended June 30, 2021, the Moderate Allocation Fund returned 8.74% before expenses and 8.73% after expenses, versus an 8.28% return for the weighted benchmark.

AGGRESSIVE ALLOCATION FUND (Unaudited)

The objective of the Aggressive Allocation Fund is capital appreciation and, to a lesser extent, current income. The Aggressive Allocation Fund invests in the equity and fixed-income funds of the Investment Company. The Aggressive Allocation Fund’s target allocation is approximately 80% of net assets in equity funds (approximately 35% of its net assets in the Equity Index Fund, 20% in the Mid-Cap Equity Index Fund, 5% each in the Small Cap Value Fund and Small Cap Growth Funds and 15% in the International Fund) and approximately 20% of net assets in the Bond Fund.

Performance for the Aggressive Allocation Fund is compared to the S&P 500^® Index (80% weighting) and the Bloomberg Barclays U.S. Aggregate Bond Index (20% weighting). For the six months ended June 30, 2021, the Aggressive Allocation Fund returned 11.75% before expenses and 11.73% after expenses, versus an 11.73% return for the weighted benchmark.

MONEY MARKET FUND (Unaudited)

The Money Market Fund’s investment objective is to realize current income while maintaining liquidity, investment quality and stability of capital through investing in high-quality commercial paper issued by U.S. corporations and securities issued by the U.S. government and its agencies. For the six months ended June 30, 2021, the Money Market Fund returned 0.07% before expenses and -0.08% after expenses, compared to a 0.03% return for the FTSE 3-Month Treasury Bill Index. Note that the benchmark performance does not reflect any expenses.

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The Fund’s strategy will continue to focus on quality, liquidity, and maintaining a relatively short weighted average maturity. On June 30, 2021, the fund held 41% in U.S. Treasury Bills, 14% in U.S. agency discount notes and the remainder in commercial paper. The average maturity was 27 days.

The seven-day effective yield as of August 17, 2021, was -0.21%. As with all performance reporting, this yield is not necessarily indicative of future annual yields. Neither the Federal Deposit Insurance Corporation nor any other U.S. government agency insures or guarantees investments in shares of the Money Market Fund.

Many of the stimulus measures put into place last year by the Federal Reserve (Fed) to combat the effects of the Covid-19 driven slowdown remain. The emergence and economic impact of the virus prompted the Fed to cut the Fed Funds target twice: an inter-meeting cut of 50 basis points on March 3, 2020 and a 100 basis point, or 1.00% easing on March 15, 2020. These actions returned the target range to 0-0.25%, a level first seen during the Global Financial Crisis of 2008-2009. This range is expected to persist into 2022 or 2023. Additionally, the Fed pledged to increase its’ holdings of Treasury securities by at least $80 billion per month and of agency mortgage-backed securities by at least $40 billion per month until progress had been made toward the goals of maximum employment and price stability. These asset purchases help foster smooth market functioning and accommodative financial conditions which supports the flow of credit to households and businesses.

In a departure from historic practice, following the September 2020 meeting, the Fed indicated that it would allow any future inflation to exceed its’ 2% target for a longer period of time relative to the past before taking action to quell price advances by raising rates. This practice has come to be known as FAIT, Flexible Average Inflation Targeting.

MID-TERM BOND FUND (Unaudited)

The Mid-Term Bond Fund seeks a high level of return consistent with the preservation of capital through investment in publicly traded debt securities. Under normal circumstances, the portfolio emphasizes corporate issues, particularly BBB-rated bonds, in order to capture incremental income. At this time, we’ve chosen to add U.S. Treasury exposure to increase the overall quality of the Fund. The objective of the Fund is to maintain a maturity profile similar to that of the Bloomberg Barclays U.S. Intermediate Government/Credit Bond Index benchmark. To achieve the duration target, intermediate corporate and U.S. Treasury maturities are emphasized. In addition, the Fund’s corporate positions will remain highly diversified in order to help shield the portfolio from any credit risks.

For the six months ended June 30, 2021, the Mid-Term Bond Fund returned -1.04% before expenses and -1.27% after expenses versus a -0.90% return of the Bloomberg Barclays Intermediate U.S. Government/Credit Bond Index during the same period. The Fund’s underperformance can be attributed in part to its’ exposure to Treasuries at the long end of the Fund’s investment range, an area that did not do well through June. In our view, the overall market has become too comfortable with risk taking. In keeping with our objective of preserving capital, we maintained our “up-in-quality” and short duration stance through this period and will continue to do so for the time being.

BOND FUND (Unaudited)

The Bond Fund’s primary investment objective is to provide as high a level of current income over time as is believed to be consistent with prudent investment risk. It does this by investing primarily in investment grade publicly traded debt securities. A secondary objective is preservation of capital. The securities held by the Bond Fund include corporate, U.S. agency and mortgage-backed securities, all of which normally yield more than U.S. Treasury issues.

Over the long term, the Bond Fund’s strategy is to overweight corporate bonds, underweight U.S. Treasuries, and market weight mortgage-backed securities. The portfolio’s aim is to maintain a similar maturity profile to the benchmark, the Bloomberg Barclays U.S. Aggregate Bond Index, with an overweighting of BBB-rated issuers. To achieve the duration target, intermediate corporate and longer U.S. Treasury maturities are emphasized. The Bond Fund also stresses diversification in order to protect it from unexpected credit events. Few corporate holdings exceed one-half of one percent of the Fund’s value. We will maintain this extreme diversification as part of our risk control.

The fixed income market posted negative returns for the first half of the year. The benchmark returned -1.60% for the six months ended June 30, 2021. The Bond Fund returned -2.02% before expenses and -2.24% after expenses during the same period. The Portfolio’s underperformance can be attributed to its’ exposure to Treasuries with long maturities, a sector that did not do well through June. In our view, the overall market has become too comfortable with risk taking. In keeping with our objective of preserving capital, we maintained our “up-in-quality” stance through this period and will continue to do so for the time being

Many of the stimulus measures put into place last year by the Federal Reserve (Fed) to combat the effects of the Covid-19 driven slowdown remain. The emergence and economic impact of the virus prompted the Fed to cut the Fed Funds target twice: an inter-meeting cut of 50 basis points on March 3, 2020 and a 100 basis point, or 1.00% easing on

9

March 15, 2020. These actions returned the target range to 0-0.25%, a level first seen during the Global Financial Crisis of 2008-2009. This range is expected to persist into 2022 or 2023. Additionally, the Fed pledged to increase its’ holdings of Treasury securities by at least $80 billion per month and of agency mortgage-backed securities by at least $40 billion per month until progress had been made toward the goals of maximum employment and price stability. These asset purchases help foster smooth market functioning and accommodative financial conditions which supports the flow of credit to households and businesses.

In a departure from historic practice, following the September 2020 meeting, the Fed indicated that it would allow any future inflation to exceed its’ 2% target for a longer period of time relative to the past before taking action to quell price advances by raising rates. This practice has come to be known as FAIT, Flexible Average Inflation Targeting.

This year has given the Fed ample opportunity to be patient as inflation, measured by the Consumer Price Index (CPI), has risen from 1.4% year-over-year (YoY) in January to 5.4% YoY in June. Fed expectations and statements that the inflation increase is transitory have had a direct and measurable effect on the markets.

Treasury yields experienced a strong updraft in the first quarter as inflation concerns drove rates higher and the yield curve steeper. From December 31, 2020 to March 31, 2021 Two-year Treasury yields rose just 4 basis points, or 0.04%, while the Ten-year yields rose 83 basis points. To put that into perspective, an 83 basis points rise in Ten-year Treasury yields equates to about a 7% loss.

The second quarter brought a reversal of both the rise in yields and the steepening of curve as long rates fell even as short rates, in anticipation of Fed action in 2023, rose slightly. It is not coincidental that rates peaked in March as the Fed became increasingly insistent that inflation is transitory and that expectations of the path of the removal of stimulus measures should be considered through that lens.

Investment grade spreads were similarly affected by the Fed’s stance that inflation is temporary and that no immediate action is required. Spreads entered 2021 close to post-economic crisis tights and exited the second quarter at levels last seen in 2005. Market considerations that the Fed would be forced to start to withdraw stimulus pushed spreads wider through March. However, Fed indications of a preference to continue as is gave a bid to corporate bonds, especially in longer dated securities, and the first half of 2021 finished the year with spreads at the tightest closing level since March 2005.

10

MUTUAL OF AMERICA INVESTMENT CORPORATION

ASSET ALLOCATIONS AS OF JUNE 30, 2021 (Unaudited)

11

MUTUAL OF AMERICA INVESTMENT CORPORATION

ASSET ALLOCATIONS AS OF JUNE 30, 2021 (Unaudited) (Continued)

12

MUTUAL OF AMERICA INVESTMENT CORPORATION

ASSET ALLOCATIONS AS OF JUNE 30, 2021 (Unaudited) (Continued)

13

MUTUAL OF AMERICA INVESTMENT CORPORATION

ASSET ALLOCATIONS AS OF JUNE 30, 2021 (Unaudited) (Continued)

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MUTUAL OF AMERICA INVESTMENT CORPORATION

ASSET ALLOCATIONS AS OF JUNE 30, 2021 (Unaudited) (Continued)

15

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited)

EXAMPLE

As a shareholder of one of the Mutual of America Investment Corporation Funds, you incur ongoing costs, including management fees and other Fund expenses. You do not incur transactional costs, such as sales charges (loads), redemption fees or exchange fees. Additionally, Mutual of America Capital Management LLC, the Funds’ Adviser, has contractually agreed to reimburse the direct non-advisory operating expenses of any Allocation or Retirement Fund (each a “Fund of Funds”) that has less than $50 million in average daily net assets for the prior calendar year. This contractual obligation remains in effect through April 30, 2022 and will continue for succeeding 12 month periods ending April 30th unless i) The Fund of Funds has at least $50 million in average daily net assets for the prior calendar year, ii) the Investment Company gives not less than 30 days written notice to the Adviser, or iii) the Adviser gives 45 days advance notice to the Investment Company before the next May 1 of a given year to terminate the agreement. In that case, the agreement will terminate on the next May 1 following the written notice. Furthermore, the Funds’ Adviser has contractually agreed to reimburse the non-advisory operating expenses of the Small Cap Equity Index and the Catholic Values Index Funds to the extent that such operating expenses exceed 0.07% of the respective fund’s net assets. This contractual obligation remains in effect through April 30, 2022 for the Small Cap Equity Index Fund and through April 30, 2023 for the Catholic Values Index Fund, and continues into successive 12 month periods ending April 30 unless i) the Investment Company gives not less than 30 days written notice to the Adviser, or ii) the Adviser gives 45 days advance notice to the Investment Company before the next May 1 of a given year to terminate the agreement. In that case, the agreement will terminate on the next May 1 following the written notice.

This Example is intended to help you understand your ongoing costs (in dollars) of investing in a 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 January 1, 2021 and held for the entire period ending June 30, 2021 under the expense reimbursement agreement in effect during that period as described above.

For variable annuity owners or participants in a group variable annuity, the estimate of expenses does not include fees and charges associated with your variable annuity. If those fees and charges were included, the estimate of expenses for the period would be higher and your ending account value would be lower.

ACTUAL EXPENSES

The first line of the tables below provides information about actual account values and actual 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 tables below provides information about hypothetical account values and hypothetical expenses based on each 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 costs of investing in the Fund with other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that 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 other non-Mutual of America funds, which may also charge transactional costs, such as sales charges (loads), redemption fees or exchange fees, which the Mutual of America Investment Corporation does not charge.

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MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

17

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

18

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

19

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

20

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

21

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

22

MUTUAL OF AMERICA INVESTMENT CORPORATION

EXPENSE EXAMPLE (Unaudited) (Continued)

23

MUTUAL OF AMERICA INVESTMENT CORPORATION — EQUITY INDEX FUND

PORTFOLIO OF INVESTMENTS IN SECURITIES

June 30, 2021 (Unaudited)

The accompanying notes are an integral part of these portfolio schedules.

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MUTUAL OF AMERICA INVESTMENT CORPORATION — EQUITY INDEX FUND

PORTFOLIO OF INVESTMENTS IN SECURITIES (Continued)

June 30, 2021 (Unaudited)

The accompanying notes are an integral part of these portfolio schedules.

25

MUTUAL OF AMERICA INVESTMENT CORPORATION — EQUITY INDEX FUND

PORTFOLIO OF INVESTMENTS IN SECURITIES (Continued)

June 30, 2021 (Unaudited)