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Summary Prospectus

October 1, 2026

VALIC Company I

Small Cap Index Fund

(Ticker: VCSLX)

The Fund’s Statutory Prospectus and Statement of Additional Information, each dated October 1, 2026, as amended and supplemented from time to time, and the most recent shareholder reports are incorporated into and made part of this Summary Prospectus by reference. The Fund is offered only to registered and unregistered separate accounts of The Variable Annuity Life Insurance Company and its affiliates and to qualifying retirement plans and IRAs and is not intended for use by other investors.

Before you invest, you may want to review the Fund’s Statutory Prospectus, which contains more information about the Fund and its risks. You can find the Statutory Prospectus and the above-incorporated information online at https://www.corebridgefinancial.com/rs/prospectus-and-reports/annuities#underlyingfunds. You can also get this information at no cost by calling 800-448-2542 or by sending an e-mail request to Forms.Request@valic.com.

The Securities and Exchange Commission has not approved or disapproved these securities, nor has it determined that this Summary Prospectus is accurate or complete. It is a criminal offense to state otherwise.

Investment Objective

The Fund seeks to provide growth of capital through investment primarily in a diversified portfolio of common stocks that, as a group, the subadviser believes may provide investment results closely corresponding to the performance of the Russell 2000® Index (the “Index”).

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. The table and the example below do not reflect the separate account fees charged in the variable annuity or variable life insurance policy (“Variable Contracts”) in which the Fund is offered. If separate account fees were shown, the Fund’s annual operating expenses would be higher. Please see your Variable Contract prospectus for more details on the separate account fees.

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

Management Fees	0.29%
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.42%
Fee Waivers and/or Expense Reimbursements1	0.06%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements1	0.36%

The Fund’s investment adviser, The Variable Annuity Life Insurance Company (“VALIC”), has contractually agreed to waive its advisory fee until September 30, 2027, so that the advisory fee payable by the Fund to VALIC equals 0.29% on the first $500 million of the Fund’s average daily net assets, 0.19% on the next $2.5 billion of the Fund’s average daily net assets, 0.14% on the next $2.0 billion of the Fund’s average daily net assets, and 0.09% on average daily net assets over

$5 billion. This agreement may be modified or discontinued prior to such time only with the approval of the Board of Directors of VALIC Company I (“VC I”), including a majority of the directors who are not “interested persons” of VC I as defined in the Investment Company Act of 1940, as amended.

Expense Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem or hold all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (except that the Example incorporates any applicable fee waiver and/or expense limitation arrangements for only the first year). The Example does not reflect charges imposed by the Variable Contract. If the separate account fees were reflected, the expenses would be higher. See the Variable Contract prospectus for information on such charges. Although your actual costs may be higher or lower, based on these assumptions and the net expenses shown in the fee table, your costs would be:

1 Year	3 Years	5 Years	10 Years
$37	$129	$229	$524

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance.

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Small Cap Index Fund

During the most recent fiscal year, the Fund’s portfolio turnover rate was 26% of the average value of its portfolio.

Principal Investment Strategies of the Fund

The Fund is managed to seek to track the performance of the Index, which measures the performance of the 2,000 smallest companies in the Russell 3000® Index, which represents approximately 10% of the total market capitalization of the Russell 3000® Index.The Subadviser may endeavor to track the Index by purchasing every stock included in the Index, in the same proportions. Or, in the alternative, the Subadviser may invest in a sampling of Index stocks by utilizing a statistical technique known as “optimization.” The goal of optimization is to select stocks which ensure that various industry weightings, market capitalizations, and fundamental characteristics (e.g., price-to-book, price-to-earnings, debt-to-asset ratios and dividend yields) closely approximate those of the Index.

The Fund invests, under normal circumstances, at least 80% of net assets in stocks that are in the Index. Although the Fund seeks to track the performance of the Index, the performance of the Fund will not match that of the Index exactly because, among other reasons, the Fund incurs operating expenses and other investment overhead as part of its normal operations. The subadviser may use derivatives to seek to track the performance of the Index, including futures and total return swaps.

In order to generate additional income, the Fund may lend portfolio securities to broker-dealers and other financial institutions provided that the value of the loaned securities does not exceed 30% of the Fund’s total assets. These loans earn income for the Fund and are collateralized by cash and securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities.

Principal Risks of Investing in the Fund

As with any mutual fund, there can be no assurance that the Fund’s investment objective will be met or that the net return on an investment in the Fund will exceed what could have been obtained through other investment or savings vehicles. Shares of the Fund are not bank deposits and are not guaranteed or insured by any bank, government entity or the Federal Deposit Insurance Corporation. If the value of the assets of the Fund goes down, you could lose money.

The following is a summary of the principal risks of investing in the Fund.

Equity Securities Risk. The Fund’s investments in equity securities are subject to the risk that stock prices will fall and may underperform other asset classes. Individual

stock prices fluctuate from day-to-day and may decline significantly. The prices of individual stocks may be negatively affected by poor company results or other factors affecting individual prices, as well as industry and/or economic trends and developments affecting industries or the securities market as a whole.

Index Risk. In attempting to track the performance of the index, the Fund may be more susceptible to adverse developments concerning a particular security, company or industry because the Fund generally will not use any defensive strategies to mitigate its risk exposure.

Failure to Match Index Performance Risk. The ability of the Fund to match the performance of the Index may be affected by, among other things, changes in securities markets, the manner in which performance of the Index is calculated, changes in the composition of the Index, the amount and timing of cash flows into and out of the Fund, commissions, portfolio expenses, and any differences in the pricing of securities by the Fund and the Index. When the Fund employs an “optimization” strategy, the Fund is subject to an increased risk of tracking error, in that the securities selected in the aggregate for the Fund may perform differently than the Index.

Small-Cap Company Risk. Investing in small-cap companies carries the risk that due to current market conditions these companies may be out of favor with investors. Small companies often are in the early stages of development with limited product lines, markets, or financial resources and managements lacking depth and experience, which may cause their stock prices to be more volatile than those of larger companies. Small company stocks may be less liquid yet subject to abrupt or erratic price movements. It may take a substantial period of time before the Fund realizes a gain on an investment in a small-cap company, if it realizes any gain at all.

Derivatives Risk. The prices of derivatives may move in unexpected ways due to the use of leverage and other factors and may result in increased volatility or losses. The Fund may not be able to terminate or sell derivative positions, and a liquid secondary market may not always exist for derivative positions.

Market Risk. The Fund’s share price can fall because of weakness in the broad market, a particular industry, or specific holdings or due to adverse social, political or economic developments here or abroad, changes in investor psychology, technological disruptions, or heavy institutional selling and other conditions or events (including, for example, military confrontations, war, terrorism, trade wars, disease/virus outbreaks and epidemics). The prices of individual securities may

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Small Cap Index Fund

fluctuate, sometimes dramatically, from day to day. The prices of stocks and other equity securities tend to be more volatile than those of fixed-income securities.

Securities Lending Risk. Engaging in securities lending could increase the market and credit risk for Fund investments. The Fund may lose money if it does not recover borrowed securities, the value of the collateral falls, or the value of investments made with cash collateral declines. The Fund’s loans will be collateralized by securities issued or guaranteed by the U.S. Government or its agencies and instrumentalities, which subjects the Fund to the credit risk of the U.S. Government or the issuing federal agency or instrumentality. If the value of either the cash collateral or the Fund’s investments of the cash collateral falls below the amount owed to a borrower, the Fund also may incur losses that exceed the amount it earned on lending the security. Securities lending also involves the risks of delay in receiving additional collateral or possible loss of rights in the collateral if the borrower fails. Another risk of securities lending is the risk that the loaned portfolio securities may not be available to the Fund on a timely basis and the Fund may therefore lose the opportunity to sell the securities at a desirable price.

Performance Information

The below bar chart and table illustrate the risks of investing in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and comparing the Fund’s average annual returns to those of the Russell 3000® Index (a broad-based securities market index) and the Russell 2000® Index, which is relevant to the Fund because it has characteristics similar to the Fund’s investment strategies. Fees and expenses incurred at the contract level are not reflected in the bar chart or table. If these amounts were reflected, returns would be less than those shown. Of course, past performance of the Fund is not necessarily an indication of how the Fund will perform in the future.

BlackRock Investment Management, LLC (“BlackRock”) assumed sub‑advisory responsibilities on April 30, 2025. Prior to this time, the Fund was subadvised by SunAmerica Asset Management, LLC.

During the period shown in the bar chart:

Highest Quarterly Return:	December 31, 2020	31.30%
Lowest Quarterly Return:	March 31, 2020	-30.69%
Year to Date Most Recent Quarter:	June 30, 2026	22.43%

Average Annual Total Returns (For the periods ended December 31, 2025)

	1 Year	5 Years	10 Years
Fund	12.23%	5.69%	9.27%
Russell 3000® Index (reflects no deduction for fees, expenses or taxes)	17.15%	13.15%	14.29%
Russell 2000® Index (reflects no deduction for fees, expenses or taxes)	12.81%	6.09%	9.62%

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Small Cap Index Fund

Investment Adviser

The Fund’s investment adviser is VALIC.

The Fund is subadvised by BlackRock.

Portfolio Managers

Name and Title	Portfolio Manager of the Fund Since
Jennifer Hsui, CFA Managing Director and Portfolio Manager	2025
Peter Sietsema, CFA Managing Director and Portfolio Manager	2025
Matt Waldron, CFA Managing Director and Portfolio Manager	2025
Steven White Director and Portfolio Manager	2025

Purchases and Sales of Fund Shares

Shares of the Funds may only be purchased or redeemed through Variable Contracts offered by the separate accounts of VALIC or other participating life insurance companies and through qualifying retirement plans (“Plans”) and IRAs. Shares of each Fund may be purchased and redeemed each day the New York Stock Exchange is open, at the Fund’s net asset value determined after receipt of a request in good order.

The Funds do not have any initial or subsequent investment minimums. However, your insurance company

may impose investment or account value minimums. The prospectus (or other offering document) for your Variable Contract contains additional information about purchases and redemptions of the Funds’ shares.

Tax Information

A Fund will not be subject to U.S. federal income tax so long as it qualifies as a regulated investment company and distributes its income and gains each year to its shareholders. However, contractholders may be subject to federal income tax (and a federal Medicare tax of 3.8% that applies to net income, including taxable annuity payments, if applicable) upon withdrawal from a Variable Contract. Contractholders should consult the prospectus (or other offering document) for the Variable Contract for additional information regarding taxation.

Payments to Broker-Dealers and
Other Financial Intermediaries

The Funds are not sold directly to the general public but instead are offered to registered and unregistered separate accounts of VALIC and its affiliates and to Plans and IRAs. The Funds and their related companies may make payments to the sponsoring insurance company or its affiliates for recordkeeping and distribution. These payments may create a conflict of interest as they may be a factor that the insurance company considers in including the Funds as underlying investment options in a variable contract. Visit your sponsoring insurance company’s website for more information.

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