Company: AILIM
Filing Date: 2025-02-18
Form Type: 10-K
Source: 0001002910-25-000055
Chunk: 302

Company: Ameren Illinois Co
Filing Date: 2025-02-18
Form: 10-K
Item: Item 7
Chunk 302
---
 estimates lost electric revenues resulting from its MEEIA customer energy-efficiency programs, which are subsequently recovered through the MEEIA rider. See Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report for a description of our regulatory mechanisms and quantification of these assets or liabilities for each of the Ameren Companies.

The following table reflects the gain and other comprehensive income, which would be offset by the removal of regulatory assets and liabilities and an increase in accumulated other comprehensive income, that would have resulted if accounting guidance for rate-regulated businesses had been eliminated as of December 31, 2024:

AmerenAmerenMissouriAmerenIllinoisGains$2,896 $1,579 $1,204 Other comprehensive income (before taxes) - pension and other postretirement benefit plan activity358 202 156 

Accounting EstimateUncertainties Affecting ApplicationBenefit Plan AccountingBased on actuarial calculations, we accrue postretirement costs of providing future employee benefits for the benefit plans we offer our employees. See Note 10 – Retirement Benefits under Part II, Item 8, of this report.•Valuation inputs and assumptions used in the fair value measurements of plan assets, excluding those inputs that are readily observable•Discount rate•Cash balance plan interest crediting rate on certain plans•Future compensation increase•Health care cost trend rates•The timing of employee retirements, terminations, benefit payments, and mortality•Ability to recover certain benefit plan costs from our customers•Changing market conditions that may affect investment and interest rate environments•Future rate of return on pension and other plan assets

Basis for Judgment

Ameren has defined benefit pension plans covering substantially all of its employees and has postretirement benefit plans covering non-union employees hired before October 2015 and union employees hired before January 2020. Our ultimate selection of the discount rate, health care trend rate, future compensation, and expected rate of return on pension and other postretirement benefit plan assets is based on our consistent application of assumption-setting methodologies, including our review of available historical, current, and projected rates, as applicable.

74

Table of Contents

The following table reflects the sensitivity of Ameren’s pension and postretirement plans to potential changes in key assumptions for the year ended December 31, 2024:

Pension BenefitsPostretirement BenefitsNet Periodic Benefit CostProjected Pension Benefit ObligationNet Periodic Benefit CostProjected Post