SEC Form 11-K filed by Simon Property Group Inc.

1. Description of the Plan

The following description of the Simon Property Group and Adopting Entities Matching Savings Plan (the Plan) provides general information about the Plan’s provisions. Simon Property Group, L.P. and affiliated companies (the Employer or the Company) is the plan sponsor. Participants should refer to the plan document for a more complete description of the Plan’s provisions, copies of which may be obtained from the plan sponsor. Simon Property Group, Inc. (SPG), a publicly traded real estate investment trust (REIT), owned a controlling 85.4% and 86.5% of Simon Property Group, L.P. at December 31, 2025 and 2024, respectively.

General

The Plan is a defined contribution plan covering substantially all employees of the Company who have at least 60 days of service and are age 21 or older.

The Plan Administrative Committee is responsible for the general administration of the Plan. Fidelity Management Trust Company is the trustee and record-keeper of the Plan. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (ERISA).

Employee Contributions

For purposes of making contributions to the Plan, employees become eligible on the first day of the month coincident with or following completion of 60 days of active employment and upon reaching age 21. Each year, participants may contribute from 1% to 50% of their before-tax compensation, as defined in the Plan. If automatically enrolled, a participant’s deferral is set at 3% of his or her eligible compensation and will increase 1% annually, with a maximum automatic contribution of 10% of eligible compensation, unless changed by the participant. Contributions are subject to maximum limitations, as defined in the Internal Revenue Code (the Code).

Employer Contributions

For the purpose of receiving the employer match and any discretionary employer contribution, an employee becomes eligible on the first day of the month coincident with or following completion of one year of eligible service (at least 1,000 hours of employment) and upon reaching age 21. The Employer currently matches 100% of eligible participants’ first 3% elected salary deductions and 50% of the participants’ next 2% elected salary deductions. In addition, the employer made discretionary profit-sharing contributions, net of forfeitures, which totaled $2,874,044 and $2,736,661 during 2025 and 2024, respectively. The discretionary contributions applied to all eligible employees, as defined. As of December 31, 2025 and 2024, unallocated participant forfeitures totaled $161,849 and $116,982, respectively, and are used to reduce future employer contributions. Forfeitures used to reduce employer contributions during 2025 were $170,222.

Participant Accounts

Each participant’s account is credited for participant contributions and allocations of the Employer’s contributions and the Plan’s earnings. Investment earnings are allocated proportionately among all participants’ accounts in an amount that bears the same ratio of their account balances to the total fund balance. The benefit to which a participant is entitled is the benefit that can be provided from the participants’ vested accounts.

2. Summary of Significant Accounting Policies

3. Tax Status

The Plan has received a determination letter from the IRS dated June 1, 2015, stating that the Plan is qualified under Section 401(a) of the Code and therefore, the related trust is exempt from taxation. Subsequent to this determination by the IRS, the Plan was amended. Once qualified, the Plan is required to operate in conformity with the Code to maintain its qualified status. The plan administrator believes the Plan is being operated in compliance with the applicable requirements of the Code and therefore, believes the Plan, as amended, is qualified and the related trust is tax-exempt.

Accounting principles generally accepted in the United States require plan management to evaluate tax positions taken by the Plan and recognize a tax liability if the Plan has taken an uncertain position that more likely than not would not be sustained upon examination by the IRS. Plan management has analyzed the tax positions taken by the Plan, and has concluded that there are no uncertain positions taken or expected to be taken. The Plan is subject to routine audits by taxing jurisdictions; however, there are currently no audits for any tax periods in progress.

4. Risks and Uncertainties

The Plan invests in various investment securities. Investment securities are exposed to various risks, such as interest rate, market volatility and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect participants’ account balances and the amounts reported in the statements of net assets available for benefits.

5. Related-Party and Party in Interest Transactions

The Plan holds units of common/collective trust funds managed by Mercer, the investment advisor of the Plan. This Plan also invests in the common stock of SPG. These transactions qualify as party-in-interest transactions; however, they are exempt from the prohibited transaction rules under ERISA. During 2025, the Plan received $1,632,678 in common stock dividends from SPG.

6. Reconciliation of Financial Statements to Form 5500

As of December 31, 2025 and 2024, net assets available for benefits per the Form 5500 totaled $674,361,626 and $597,638,417, respectively, and are equal to the net assets available for benefits per the financial statements. There were no reconciliation differences for 2025 and 2024.

The benefits paid to participants per the Form 5500 for the year ended December 31, 2025 totaled $61,814,920 and is equal to the benefits paid to participants per the financial statements with no reconciling differences.

7. Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., an exit price). The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value.

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3).

The three levels of the fair value hierarchy are described below:

8. Subsequent Event

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On October 31, 2025, the Company closed on the acquisition of the remaining 12% interest in The Taubman Realty Group, LLC (TRG) which it did not previously own. As a result of this acquisition, the Company obtained control of and consolidated TRG. Effective January 1, 2026, former employees of TRG who remained active and became employees of the Company began participating in the Plan.

Simon Property Group and Adopting Entities Matching Savings Plan

Schedule H, Line 4i — Schedule of Assets

(Held at End of Year)

EIN 34-1755769     Plan #002

December 31, 2025