Company: AILIM
Filing Date: 2025-02-18
Form Type: 10-K
Source: 0001002910-25-000055
Chunk: 107

Company: Ameren Illinois Co
Filing Date: 2025-02-18
Form: 10-K
Item: Item 8
Chunk 107
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 TSR performance. The key assumptions used to calculate fair value also include a three-year risk-free rate, Ameren’s common stock volatility, and volatility for the peer group. The following table presents the fair value of each share unit along with the significant assumptions used to calculate the fair value of each share unit for the years ended December 31, 2024, 2023, and 2022:202420232022Fair value of share units awarded$56.73$91.07$92.75Three-year risk-free rate4.25%4.19%1.80%Ameren’s common stock volatility(a)21%26%29%Volatility range for the peer group(a)19% – 23%24% – 32%26% – 35%(a)Based on a historical period that is equal to the remaining term of the performance period as of the grant date.In addition to the market condition performance share units described above, there are an immaterial number of market condition performance share units with different vesting conditions and target payout percentages.

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Performance Share Units – Performance ConditionA performance condition share unit vests and entitles an employee to receive shares of Ameren common stock (plus accumulated dividends) if, at the end of the three-year performance period, Ameren has met the specified performance condition and if the individual remains employed by Ameren through the required vesting period. The vesting period for share units awarded extends beyond the three-year performance period to the payout date, which is approximately 38 months after the grant date. In the event of a participant’s death or retirement at age 55 or older with five years or more of service, awards vest on a pro-rata basis over the three-year performance period. The exact number of shares issued pursuant to a share unit varies from 0% to 200% of the target award, depending on actual performance conditions achieved. The specified performance condition in each award year is based on Ameren’s clean energy transition. The grant-date fair value for an individual outcome of a performance condition is determined by Ameren’s closing common share price on the grant date.Restricted Stock UnitsRestricted stock units vest and entitle an employee to receive shares of Ameren common stock (plus accumulated dividends) if the individual remains employed with Ameren through the payment date of the awards. Generally, in the event of a participant’s death or retirement at age 55 or older with five years or more of service, awards vest on a pro-rata