Retirement Benefits (Tables)

12 Months Ended

Dec. 31, 2018

The following table presents the net benefit liability recorded on the balance sheets of each of the Ameren Companies as of December 31, 2018 and 2017:



	2018		2017
Ameren^(a)	$	481	$	551
Ameren Missouri	229		215
Ameren Illinois^(a)	120		213


(a)	Assets associated with other postretirement benefits are recorded in “Other assets” on the balance sheet.

Funded Status Of Benefit Plans And Amounts Included In Regulatory Assets And OCI

The following table presents the funded status of Ameren’s pension and postretirement benefit plans as of December 31, 2018 and 2017. It also provides the amounts included in regulatory assets and accumulated OCI at December 31, 2018 and 2017, that have not been recognized in net periodic benefit costs.



	2018						2017
	Pension Benefits				Postretirement Benefits		Pension Benefits				Postretirement Benefits
Accumulated benefit obligation at end of year	$	4,258		$	(a)		$	4,577		$	(a)
Change in benefit obligation:
Net benefit obligation at beginning of year	$	4,827		$	1,240		$	4,518		$	1,170
Service cost	100				21		93				21
Interest cost	169				40		179				47
Plan amendments	—				(49	)	—				—
Participant contributions	—				9		—				8
Actuarial (gain) loss	(401		)		(163	)	255				53
Benefits paid	(236		)		(64	)	(218		)		(59	)
Net benefit obligation at end of year	4,459				1,034		4,827				1,240
Change in plan assets:
Fair value of plan assets at beginning of year	4,293				1,223		3,813				1,101
Actual return on plan assets	(218		)		(57	)	634				171
Employer contributions	60				2		64				2
Participant contributions	—				9		—				8
Benefits paid	(236		)		(64	)	(218		)		(59	)
Fair value of plan assets at end of year	3,899				1,113		4,293				1,223
Funded status – deficiency (surplus)	560				(79	)	534				17
Accrued benefit cost (asset) at December 31	$	560		$	(79	)	$	534		$	17
Amounts recognized in the balance sheet consist of:
Noncurrent asset^(b)	$	—		$	(79	)	$	—		$	—
Current liability^(c)	2				—		3				3
Noncurrent liability	558				—		531				14
Net liability (asset) recognized	$	560		$	(79	)	$	534		$	17
Amounts recognized in regulatory assets consist of:
Net actuarial (gain) loss	$	393		$	(91	)	$	374		$	(69	)
Prior service credit	(2		)		(48	)	(3		)		(3	)
Amounts (pretax) recognized in accumulated OCI consist of:
Net actuarial loss	35				3		30				2
Total	$	426		$	(136	)	$	401		$	(70	)


(a)	Not applicable.


(b)	Included in “Other assets” on Ameren’s consolidated balance sheet.


(c)	Included in “Other current liabilities” on Ameren’s consolidated balance sheet.

Assumptions Used To Determine Benefit Obligations

The following table presents the assumptions used to determine our benefit obligations at December 31, 2018 and 2017:



	Pension Benefits				Postretirement Benefits
	2018		2017		2018		2017
Discount rate at measurement date	4.25	%	3.50	%	4.25	%	3.50	%
Increase in future compensation	3.50		3.50		3.50		3.50
Medical cost trend rate (initial)^(a)	(b)		(b)		5.00		5.00
Medical cost trend rate (ultimate)^(a)	(b)		(b)		5.00		5.00


(a)	Initial and ultimate medical cost trend rate for certain Medicare-eligible participants is 3.00%.


(b)	Not applicable

Schedule Of Cash Contributions Made To Benefit Plans

The following table presents the cash contributions made to our defined benefit retirement plan and to our postretirement plans during 2018, 2017, and 2016:



	Pension Benefits						Postretirement Benefits
	2018		2017		2016		2018		2017		2016
Ameren Missouri	$	18	$	19	$	21	$	1	$	1	$	1
Ameren Illinois	35		37		30		1		1		1
Other	7		8		6		—		—		—
Ameren	$	60	$	64	$	57	$	2	$	2	$	2

Target Allocation Of The Plans' Asset Categories

The following table presents our target allocations for 2019 and our pension and postretirement plans’ asset categories as of December 31, 2018 and 2017:



Asset Category	Target Allocation 2019	Percentage of Plan Assets at December 31,
Asset Category	Target Allocation 2019	2018		2017
Pension Plan:
Cash and cash equivalents	0% – 5%	1	%	1	%
Equity securities:
U.S. large-capitalization	21% – 31%	24	%	34	%
U.S. small- and mid-capitalization	3% – 13%	7	%	9	%
International	9% – 19%	13	%	14	%
Global	3% – 13%	8	%	—	%
Total equity	51% – 61%	52	%	57	%
Debt securities	35% – 45%	42	%	37	%
Real estate	0% – 9%	5	%	5	%
Private equity	0% – 5%	(a)		(a)
Total		100	%	100	%
Postretirement Plans:
Cash and cash equivalents	0% – 7%	2	%	2	%
Equity securities:
U.S. large-capitalization	34% – 44%	40	%	41	%
U.S. small- and mid-capitalization	2% – 12%	7	%	8	%
International	9% – 19%	13	%	14	%
Total equity	55% – 65%	60	%	63	%
Debt securities	33% – 43%	38	%	35	%
Total		100	%	100	%


(a)	Less than 1% of plan assets.

Components Of Net Periodic Benefit Cost

The following table presents the components of the net periodic benefit cost of Ameren’s pension and postretirement benefit plans during 2018, 2017, and 2016:



	Pension Benefits			Postretirement Benefits
2018
Service cost^(a)	$	100		$	21
Non-service cost components:
Interest cost	169			40
Expected return on plan assets	(276		)	(77		)
Amortization of:
Prior service credit	(1		)	(4		)
Actuarial (gain) loss	68			(6		)
Total non-service cost components^(b)	$	(40	)	$	(47	)
Net periodic benefit cost (income)	$	60		$	(26	)
2017
Service cost^(a)	$	93		$	21
Non-service cost components:
Interest cost	179			47
Expected return on plan assets	(262		)	(75		)
Amortization of:
Prior service credit	(1		)	(5		)
Actuarial (gain) loss	55			(6		)
Total non-service cost components^(b)	$	(29	)	$	(39	)
Net periodic benefit cost (income)	$	64		$	(18	)
2016
Service cost^(a)	$	81		$	19
Non-service cost components:
Interest cost	185			50
Expected return on plan assets	(253		)	(72		)
Amortization of:
Prior service credit	(1		)	(5		)
Actuarial (gain) loss	32			(11		)
Total non-service cost components^(b)	$	(37	)	$	(38	)
Net periodic benefit cost (income)	$	44		$	(19	)

(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 and 2016’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.

Summary Of Estimated Amortizable Amounts From Regulatory Assets and Accumulated OCI Into Net Periodic Benefit Cost

The estimated amounts that will be amortized from regulatory assets and accumulated OCI into Ameren’s net periodic benefit cost in 2019 are as follows:



	Pension Benefits			Postretirement Benefits
Regulatory assets:
Prior service credit	$	(1	)	$	(5	)
Net actuarial (gain) loss	24			(15		)
Accumulated OCI:
Net actuarial loss	2			—
Total	$	25		$	(20	)

Summary Of Benefit Plan Costs Incurred

The Ameren Companies are responsible for their share of the pension and postretirement benefit costs. The following table presents the pension costs and the postretirement benefit costs incurred for the years ended December 31, 2018, 2017, and 2016:



	Pension Costs									Postretirement Costs
	2018			2017			2016			2018			2017			2016
Ameren Missouri^(a)	$	22		$	24		$	26		$	(1	)	$	(4	)	$	(5	)
Ameren Illinois	39			41			22			(25		)	(14		)	(13		)
Other	(1		)	(1		)	(4		)	—			—			(1		)
Ameren	60			64			44			(26		)	(18		)	(19		)


(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 and the level of such costs included in customer rates.

Schedule Of Expected Payments From Qualified Trust And Company Funds

The expected pension and postretirement benefit payments from qualified trust and company funds, which reflect expected future service, as of December 31, 2018, are as follows:



	Pension Benefits				Postretirement Benefits
	Paid from Qualified Trust Funds		Paid from Company Funds		Paid from Qualified Trust Funds		Paid from Company Funds
2019	$	267	$	3	$	57	$	2
2020	272		3		59		2
2021	282		3		61		2
2022	285		3		62		2
2023	286		3		64		2
2024 – 2028	1,439		12		315		12

Assumptions Used To Determine Net Periodic Benefit Cost

The following table presents the assumptions used to determine net periodic benefit cost for our pension and postretirement benefit plans for the years ended December 31, 2018, 2017, and 2016:



	Pension Benefits						Postretirement Benefits
	2018		2017		2016		2018		2017		2016
Discount rate at measurement date	3.50	%	4.00	%	4.50	%	3.50	%	4.00	%	4.50	%
Expected return on plan assets	7.00		7.00		7.00		7.00		7.00		7.00
Increase in future compensation	3.50		3.50		3.50		3.50		3.50		3.50
Medical cost trend rate (initial)^(a)	(b)		(b)		(b)		5.00		5.00		5.00
Medical cost trend rate (ultimate)^(a)	(b)		(b)		(b)		5.00		5.00		5.00


(a)	Initial and ultimate medical cost trend rate for certain Medicare-eligible participants is 3.00%.


(b)	Not applicable

Schedule Of Potential Changes In Key Assumptions

The table below reflects the sensitivity of Ameren’s plans to potential changes in key assumptions:



	Pension Benefits					Postretirement Benefits
	Service Cost and Interest Cost			Projected Benefit Obligation		Service Cost and Interest Cost			Postretirement Benefit Obligation
0.25% decrease in discount rate	$	(2	)	$	135	$	—		$	33
0.25% increase in salary scale	2			12		—			—
1.00% increase in annual medical trend	—			—		4			58
1.00% decrease in annual medical trend	—			—		(4		)	(58		)

Schedule Of Matching Contributions

The following table presents the portion of the matching contribution to the Ameren 401(k) plan attributable to each of the Ameren Companies for the years ended December 31, 2018, 2017, and 2016:



	2018		2017		2016
Ameren Missouri	$	17	$	16	$	16
Ameren Illinois	15		13		12
Other	1		1		1
Ameren	$	33	$	30	$	29

Pension Benefits

Target Allocation Of The Plans' Asset Categories

The following table sets forth, by level within the fair value hierarchy discussed in Note 8 – Fair Value Measurements, the pension plans’ assets measured at fair value as of December 31, 2018:



	Quoted Prices in Active Markets for Identified Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)		Measured at NAV		Total
Cash and cash equivalents	$	—	$	—	$	—	$	41	$	41
Equity securities:
U.S. large-capitalization	—		—		—		955		955
U.S. small- and mid-capitalization	272		—		—		—		272
International	224		—		—		298		522
Global	—		—		—		321		321
Debt securities:
Corporate bonds	—		701		—		19		720
Municipal bonds	—		87		—		—		87
U.S. Treasury and agency securities	—		891		—		—		891
Other	1		11		—		—		12
Real estate	—		—		—		202		202
Private equity	—		—		—		3		3
Total	$	497	$	1,690	$	—	$	1,839	$	4,026
Less: Medical benefit assets at December 31^(a)									(144		)
Plus: Net receivables at December 31^(b)									17
Fair value of pension plans’ assets at December 31									$	3,899


(a)	Medical benefit (health and welfare) component for accounts maintained in accordance with Section 401(h) of the Internal Revenue Code to fund a portion of the postretirement obligation.


(b)	Receivables related to pending security sales, offset by payables related to pending security purchases.

The following table sets forth, by level within the fair value hierarchy discussed in Note 8 – Fair Value Measurements, the pension plans’ assets measured at fair value as of December 31, 2017:



	Quoted Prices in Active Markets for Identified Assets or Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)		Measured at NAV		Total
Cash and cash equivalents	$	—	$	—	$	—	$	25	$	25
Equity securities:
U.S. large-capitalization	—		—		—		1,523		1,523
U.S. small- and mid-capitalization	379		—		—		—		379
International	179		—		—		450		629
Debt securities:
Corporate bonds	—		726		—		15		741
Municipal bonds	—		91		—		—		91
U.S. Treasury and agency securities	8		816		—		—		824
Other	—		7		—		—		7
Real estate	—		—		—		196		196
Private equity	—		—		—		4		4
Total	$	566	$	1,640	$	—	$	2,213	$	4,419
Less: Medical benefit assets at December 31^(a)									(153		)
Plus: Net receivables at December 31^(b)									27
Fair value of pension plans’ assets at December 31									$	4,293


(a)	Medical benefit (health and welfare) component for accounts maintained in accordance with Section 401(h) of the Internal Revenue Code to fund a portion of the postretirement obligation.


(b)	Receivables related to pending security sales, offset by payables related to pending security purchases.

Postretirement Benefits

Target Allocation Of The Plans' Asset Categories

The following table sets forth, by level within the fair value hierarchy discussed in Note 8 – Fair Value Measurements, the postretirement benefit plans’ assets measured at fair value as of December 31, 2018:



	Quoted Prices in Active Markets for Identified Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)		Measured at NAV		Total
Cash and cash equivalents	$	32	$	—	$	—	$	—	$	32
Equity securities:
U.S. large-capitalization	297		—		—		89		386
U.S. small- and mid-capitalization	63		—		—		—		63
International	45		—		—		84		129
Other	—		12		—		—		12
Debt securities:
Corporate bonds	—		144		—		—		144
Municipal bonds	—		107		—		—		107
U.S. Treasury and agency securities	—		62		—		—		62
Other	—		7		—		34		41
Total	$	437	$	332	$	—	$	207	$	976
Plus: Medical benefit assets at December 31^(a)									144
Less: Net payables at December 31^(b)									(7		)
Fair value of postretirement benefit plans’ assets at December 31									$	1,113


(a)	Medical benefit (health and welfare) component for 401(h) accounts to fund a portion of the postretirement obligation. These 401(h) assets are included in the pension plan assets shown above.


(b)	Payables related to pending security purchases, offset by interest receivables and receivables related to pending security sales.



	Quoted Prices in Active Markets for Identified Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)		Measured at NAV		Total
Cash and cash equivalents	$	44	$	—	$	—	$	—	$	44
Equity securities:
U.S. large-capitalization	332		—		—		110		442
U.S. small- and mid-capitalization	80		—		—		—		80
International	53		—		—		101		154
Other	—		8		—		—		8
Debt securities:
Corporate bonds	—		144		—		—		144
Municipal bonds	—		110		—		—		110
U.S. Treasury and agency securities	—		76		—		—		76
Other	—		4		—		34		38
Total	$	509	$	342	$	—	$	245	$	1,096
Plus: Medical benefit assets at December 31^(a)									153
Less: Net payables at December 31^(b)									(26		)
Fair value of postretirement benefit plans’ assets at December 31									$	1,223


(a)	Medical benefit (health and welfare) component for 401(h) accounts to fund a portion of the postretirement obligation. These 401(h) assets are included in the pension plan assets shown above.


(b)	Payables related to pending security purchases, offset by interest receivables and receivables related to pending security sales.