RETIREMENT BENEFITS

In March 2017, the FASB issued authoritative guidance that requires an entity to report, including on a retrospective basis, the non-service cost or income components of net periodic benefit cost separately from the service cost component and outside of operating income. The Ameren Companies adopted this guidance, effective January 1, 2018, and as a result, $33 million, $17 million, and $8 million of net benefit income has been retrospectively reclassified from “Operating Expenses – Other operations and maintenance” to “Other Income, Net” on Ameren's, Ameren Missouri’s, and Ameren Illinois’ respective statements of income for the nine months ended September 30, 2017. Net benefit income of $11 million, $5 million, and $4 million has been similarly retrospectively reclassified on Ameren’s, Ameren Missouri’s, and Ameren Illinois’ respective statements of income for the three months ended September 30, 2017.

The guidance also requires an entity to capitalize only the service cost component as part of an asset, such as inventory or property, plant, and equipment, on a prospective basis. Previously all of the net benefit cost components were eligible for capitalization. This change in the capitalization of net benefit costs is not expected to affect our ability to recover total net benefit cost through customer rates.

The following table presents the components of the net periodic benefit cost (income), prior to capitalization, incurred for Ameren’s pension and postretirement benefit plans for the three and nine months ended September 30, 2018 and 2017:



	Pension Benefits												Postretirement Benefits
	Three Months						Nine Months						Three Months						Nine Months
	2018			2017			2018			2017			2018			2017			2018			2017
Service cost^(a)	$	25		$	24		$	75		$	70		$	6		$	6		$	16		$	16
Non-service cost components:
Interest cost	42			44			126			134			10			12			30			35
Expected return on plan assets	(68		)	(65		)	(206		)	(196		)	(20		)	(19		)	(58		)	(56		)
Amortization of:
Prior service benefit	—			(1		)	—			(1		)	(1		)	(2		)	(3		)	(4		)
Actuarial loss (gain)	17			14			51			41			(2		)	(2		)	(5		)	(5		)
Total non-service cost components^(b)	(9		)	(8		)	(29		)	(22		)	(13		)	(11		)	(36		)	(30		)
Net periodic benefit cost (income)	$	16		$	16		$	46		$	48		$	(7	)	$	(5	)	$	(20	)	$	(14	)


(a)	Service cost, net of capitalization, is reflected in “Operating Expenses – Other operations and maintenance” on Ameren’s statement of income.


(b)	2018 amounts and the non-capitalized portion of 2017’s non-service cost components, as discussed above, are reflected in “Other Income, Net” on Ameren’s statement of income. See Note 5 – Other Income, Net for additional information.

Ameren Missouri and Ameren Illinois are responsible for their respective shares of Ameren’s pension and postretirement costs. The following table presents the respective share of net periodic pension and other postretirement benefit costs (income) incurred for the three and nine months ended September 30, 2018 and 2017:



	Pension Benefits										Postretirement Benefits
	Three Months					Nine Months					Three Months						Nine Months
	2018			2017		2018			2017		2018			2017			2018			2017
Ameren Missouri^(a)	$	6		$	6	$	17		$	18	$	(1	)	$	(1	)	$	(1	)	$	(3	)
Ameren Illinois	11			10		30			30		(6		)	(3		)	(19		)	(10		)
Other	(1		)	—		(1		)	—		—			(1		)	—			(1		)
Ameren^(a)	$	16		$	16	$	46		$	48	$	(7	)	$	(5	)	$	(20	)	$	(14	)


(a)	Does not include the impact of the regulatory tracking mechanism for the difference between the level of pension and postretirement benefit costs incurred by Ameren Missouri under GAAP and the level of such costs included in rates.