Short-Term Debt and Liquidity (Tables)

3 Months Ended

Mar. 31, 2025

Debt Disclosure [Abstract]

Schedule of Short-term Debt

The following table presents commercial paper outstanding, net of issuance discounts, as of March 31, 2025, and December 31, 2024. There were no borrowings outstanding under the Credit Agreements as of March 31, 2025, or December 31, 2024.

	March 31, 2025		December 31, 2024
Ameren (parent)	$	434	$	1,055
Ameren Missouri	629		—
Ameren Illinois	189		88
Ameren consolidated	$	1,252	$	1,143

The following table summarizes the activity and relevant interest rates for Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper issuances under the Credit Agreements for the three months ended March 31, 2025 and 2024:

	Ameren (parent)			Ameren Missouri			Ameren Illinois			Ameren Consolidated
2025
Average daily amount outstanding	$	898		$	313		$	82		$	1,293
Weighted-average interest rate	4.61		%	4.59		%	4.56		%	4.60		%
Peak amount outstanding during period(a)	$	1,139		$	630		$	189		$	1,603
Peak interest rate	4.75		%	4.70		%	4.69		%	4.75		%
2024
Average daily amount outstanding	$	—		$	135		$	336		$	471
Weighted-average interest rate	—		%	5.53		%	5.58		%	5.57		%
Peak amount outstanding during period(a)	$	—		$	444		$	425		$	869
Peak interest rate	—		%	5.68		%	5.68		%	5.68		%

(a)The timing of peak outstanding commercial paper issuances under the Credit Agreements varies by company. Therefore, the sum of individual company peak amounts may not equal the Ameren consolidated peak amount for the period.