Benefit Plans

3 Months Ended

Mar. 31, 2017

Benefit Plans

BENEFIT PLANS

The disclosures in this note apply to all Registrants unless indicated otherwise.

AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans.  Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan.  AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees.

Components of Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans:

AEP

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	24.1		$	21.4		$	2.8		$	2.6
Interest Cost	50.8			52.9			14.8			15.2
Expected Return on Plan Assets	(71.2		)	(70.1		)	(25.3		)	(26.8		)
Amortization of Prior Service Cost (Credit)	0.3			0.6			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	20.7			21.0			9.2			7.9
Net Periodic Benefit Cost (Credit)	$	24.7		$	25.8		$	(15.8	)	$	(18.4	)

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.3		$	2.0		$	0.3		$	0.2
Interest Cost	6.4			6.8			2.6			2.7
Expected Return on Plan Assets	(8.9		)	(8.8		)	(4.1		)	(4.3		)
Amortization of Prior Service Cost (Credit)	0.1			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.7			1.6			1.4
Net Periodic Benefit Cost (Credit)	$	2.5		$	2.7		$	(2.1	)	$	(2.5	)

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	3.5		$	3.0		$	0.4		$	0.4
Interest Cost	6.1			6.3			1.7			1.8
Expected Return on Plan Assets	(8.6		)	(8.4		)	(3.1		)	(3.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(2.3		)	(2.4		)
Amortization of Net Actuarial Loss	2.4			2.5			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	3.4		$	3.5		$	(2.2	)	$	(2.5	)

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.9		$	1.6		$	0.2		$	0.2
Interest Cost	4.8			5.2			1.7			1.7
Expected Return on Plan Assets	(7.0		)	(6.9		)	(3.0		)	(3.2		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(1.7	)	$	(2.1	)

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.6		$	1.5		$	0.2		$	0.2
Interest Cost	2.7			2.8			0.8			0.8
Expected Return on Plan Assets	(3.9		)	(3.9		)	(1.4		)	(1.5		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.5			0.4
Net Periodic Benefit Cost (Credit)	$	1.5		$	1.6		$	(1.0	)	$	(1.2	)

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.2		$	2.0		$	0.2		$	0.2
Interest Cost	3.1			3.1			0.9			0.9
Expected Return on Plan Assets	(4.2		)	(4.1		)	(1.6		)	(1.7		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.2			1.2			0.6			0.5
Net Periodic Benefit Cost (Credit)	$	2.3		$	2.3		$	(1.2	)	$	(1.4	)

Appalachian Power Co [Member]

Benefit Plans

BENEFIT PLANS

The disclosures in this note apply to all Registrants unless indicated otherwise.

AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans.  Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan.  AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees.

Components of Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans:

AEP

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	24.1		$	21.4		$	2.8		$	2.6
Interest Cost	50.8			52.9			14.8			15.2
Expected Return on Plan Assets	(71.2		)	(70.1		)	(25.3		)	(26.8		)
Amortization of Prior Service Cost (Credit)	0.3			0.6			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	20.7			21.0			9.2			7.9
Net Periodic Benefit Cost (Credit)	$	24.7		$	25.8		$	(15.8	)	$	(18.4	)

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.3		$	2.0		$	0.3		$	0.2
Interest Cost	6.4			6.8			2.6			2.7
Expected Return on Plan Assets	(8.9		)	(8.8		)	(4.1		)	(4.3		)
Amortization of Prior Service Cost (Credit)	0.1			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.7			1.6			1.4
Net Periodic Benefit Cost (Credit)	$	2.5		$	2.7		$	(2.1	)	$	(2.5	)

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	3.5		$	3.0		$	0.4		$	0.4
Interest Cost	6.1			6.3			1.7			1.8
Expected Return on Plan Assets	(8.6		)	(8.4		)	(3.1		)	(3.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(2.3		)	(2.4		)
Amortization of Net Actuarial Loss	2.4			2.5			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	3.4		$	3.5		$	(2.2	)	$	(2.5	)

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.9		$	1.6		$	0.2		$	0.2
Interest Cost	4.8			5.2			1.7			1.7
Expected Return on Plan Assets	(7.0		)	(6.9		)	(3.0		)	(3.2		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(1.7	)	$	(2.1	)

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.6		$	1.5		$	0.2		$	0.2
Interest Cost	2.7			2.8			0.8			0.8
Expected Return on Plan Assets	(3.9		)	(3.9		)	(1.4		)	(1.5		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.5			0.4
Net Periodic Benefit Cost (Credit)	$	1.5		$	1.6		$	(1.0	)	$	(1.2	)

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.2		$	2.0		$	0.2		$	0.2
Interest Cost	3.1			3.1			0.9			0.9
Expected Return on Plan Assets	(4.2		)	(4.1		)	(1.6		)	(1.7		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.2			1.2			0.6			0.5
Net Periodic Benefit Cost (Credit)	$	2.3		$	2.3		$	(1.2	)	$	(1.4	)

Indiana Michigan Power Co [Member]

Benefit Plans

BENEFIT PLANS

The disclosures in this note apply to all Registrants unless indicated otherwise.

AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans.  Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan.  AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees.

Components of Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans:

AEP

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	24.1		$	21.4		$	2.8		$	2.6
Interest Cost	50.8			52.9			14.8			15.2
Expected Return on Plan Assets	(71.2		)	(70.1		)	(25.3		)	(26.8		)
Amortization of Prior Service Cost (Credit)	0.3			0.6			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	20.7			21.0			9.2			7.9
Net Periodic Benefit Cost (Credit)	$	24.7		$	25.8		$	(15.8	)	$	(18.4	)

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.3		$	2.0		$	0.3		$	0.2
Interest Cost	6.4			6.8			2.6			2.7
Expected Return on Plan Assets	(8.9		)	(8.8		)	(4.1		)	(4.3		)
Amortization of Prior Service Cost (Credit)	0.1			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.7			1.6			1.4
Net Periodic Benefit Cost (Credit)	$	2.5		$	2.7		$	(2.1	)	$	(2.5	)

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	3.5		$	3.0		$	0.4		$	0.4
Interest Cost	6.1			6.3			1.7			1.8
Expected Return on Plan Assets	(8.6		)	(8.4		)	(3.1		)	(3.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(2.3		)	(2.4		)
Amortization of Net Actuarial Loss	2.4			2.5			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	3.4		$	3.5		$	(2.2	)	$	(2.5	)

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.9		$	1.6		$	0.2		$	0.2
Interest Cost	4.8			5.2			1.7			1.7
Expected Return on Plan Assets	(7.0		)	(6.9		)	(3.0		)	(3.2		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(1.7	)	$	(2.1	)

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.6		$	1.5		$	0.2		$	0.2
Interest Cost	2.7			2.8			0.8			0.8
Expected Return on Plan Assets	(3.9		)	(3.9		)	(1.4		)	(1.5		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.5			0.4
Net Periodic Benefit Cost (Credit)	$	1.5		$	1.6		$	(1.0	)	$	(1.2	)

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.2		$	2.0		$	0.2		$	0.2
Interest Cost	3.1			3.1			0.9			0.9
Expected Return on Plan Assets	(4.2		)	(4.1		)	(1.6		)	(1.7		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.2			1.2			0.6			0.5
Net Periodic Benefit Cost (Credit)	$	2.3		$	2.3		$	(1.2	)	$	(1.4	)

Ohio Power Co [Member]

Benefit Plans

BENEFIT PLANS

The disclosures in this note apply to all Registrants unless indicated otherwise.

AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans.  Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan.  AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees.

Components of Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans:

AEP

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	24.1		$	21.4		$	2.8		$	2.6
Interest Cost	50.8			52.9			14.8			15.2
Expected Return on Plan Assets	(71.2		)	(70.1		)	(25.3		)	(26.8		)
Amortization of Prior Service Cost (Credit)	0.3			0.6			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	20.7			21.0			9.2			7.9
Net Periodic Benefit Cost (Credit)	$	24.7		$	25.8		$	(15.8	)	$	(18.4	)

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.3		$	2.0		$	0.3		$	0.2
Interest Cost	6.4			6.8			2.6			2.7
Expected Return on Plan Assets	(8.9		)	(8.8		)	(4.1		)	(4.3		)
Amortization of Prior Service Cost (Credit)	0.1			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.7			1.6			1.4
Net Periodic Benefit Cost (Credit)	$	2.5		$	2.7		$	(2.1	)	$	(2.5	)

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	3.5		$	3.0		$	0.4		$	0.4
Interest Cost	6.1			6.3			1.7			1.8
Expected Return on Plan Assets	(8.6		)	(8.4		)	(3.1		)	(3.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(2.3		)	(2.4		)
Amortization of Net Actuarial Loss	2.4			2.5			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	3.4		$	3.5		$	(2.2	)	$	(2.5	)

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.9		$	1.6		$	0.2		$	0.2
Interest Cost	4.8			5.2			1.7			1.7
Expected Return on Plan Assets	(7.0		)	(6.9		)	(3.0		)	(3.2		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(1.7	)	$	(2.1	)

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.6		$	1.5		$	0.2		$	0.2
Interest Cost	2.7			2.8			0.8			0.8
Expected Return on Plan Assets	(3.9		)	(3.9		)	(1.4		)	(1.5		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.5			0.4
Net Periodic Benefit Cost (Credit)	$	1.5		$	1.6		$	(1.0	)	$	(1.2	)

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.2		$	2.0		$	0.2		$	0.2
Interest Cost	3.1			3.1			0.9			0.9
Expected Return on Plan Assets	(4.2		)	(4.1		)	(1.6		)	(1.7		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.2			1.2			0.6			0.5
Net Periodic Benefit Cost (Credit)	$	2.3		$	2.3		$	(1.2	)	$	(1.4	)

Public Service Co Of Oklahoma [Member]

Benefit Plans

BENEFIT PLANS

The disclosures in this note apply to all Registrants unless indicated otherwise.

AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans.  Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan.  AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees.

Components of Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans:

AEP

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	24.1		$	21.4		$	2.8		$	2.6
Interest Cost	50.8			52.9			14.8			15.2
Expected Return on Plan Assets	(71.2		)	(70.1		)	(25.3		)	(26.8		)
Amortization of Prior Service Cost (Credit)	0.3			0.6			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	20.7			21.0			9.2			7.9
Net Periodic Benefit Cost (Credit)	$	24.7		$	25.8		$	(15.8	)	$	(18.4	)

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.3		$	2.0		$	0.3		$	0.2
Interest Cost	6.4			6.8			2.6			2.7
Expected Return on Plan Assets	(8.9		)	(8.8		)	(4.1		)	(4.3		)
Amortization of Prior Service Cost (Credit)	0.1			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.7			1.6			1.4
Net Periodic Benefit Cost (Credit)	$	2.5		$	2.7		$	(2.1	)	$	(2.5	)

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	3.5		$	3.0		$	0.4		$	0.4
Interest Cost	6.1			6.3			1.7			1.8
Expected Return on Plan Assets	(8.6		)	(8.4		)	(3.1		)	(3.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(2.3		)	(2.4		)
Amortization of Net Actuarial Loss	2.4			2.5			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	3.4		$	3.5		$	(2.2	)	$	(2.5	)

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.9		$	1.6		$	0.2		$	0.2
Interest Cost	4.8			5.2			1.7			1.7
Expected Return on Plan Assets	(7.0		)	(6.9		)	(3.0		)	(3.2		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(1.7	)	$	(2.1	)

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.6		$	1.5		$	0.2		$	0.2
Interest Cost	2.7			2.8			0.8			0.8
Expected Return on Plan Assets	(3.9		)	(3.9		)	(1.4		)	(1.5		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.5			0.4
Net Periodic Benefit Cost (Credit)	$	1.5		$	1.6		$	(1.0	)	$	(1.2	)

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.2		$	2.0		$	0.2		$	0.2
Interest Cost	3.1			3.1			0.9			0.9
Expected Return on Plan Assets	(4.2		)	(4.1		)	(1.6		)	(1.7		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.2			1.2			0.6			0.5
Net Periodic Benefit Cost (Credit)	$	2.3		$	2.3		$	(1.2	)	$	(1.4	)

Southwestern Electric Power Co [Member]

Benefit Plans

BENEFIT PLANS

The disclosures in this note apply to all Registrants unless indicated otherwise.

AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans.  Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan.  AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees.

Components of Net Periodic Benefit Cost

The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans:

AEP

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	24.1		$	21.4		$	2.8		$	2.6
Interest Cost	50.8			52.9			14.8			15.2
Expected Return on Plan Assets	(71.2		)	(70.1		)	(25.3		)	(26.8		)
Amortization of Prior Service Cost (Credit)	0.3			0.6			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	20.7			21.0			9.2			7.9
Net Periodic Benefit Cost (Credit)	$	24.7		$	25.8		$	(15.8	)	$	(18.4	)

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.3		$	2.0		$	0.3		$	0.2
Interest Cost	6.4			6.8			2.6			2.7
Expected Return on Plan Assets	(8.9		)	(8.8		)	(4.1		)	(4.3		)
Amortization of Prior Service Cost (Credit)	0.1			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.7			1.6			1.4
Net Periodic Benefit Cost (Credit)	$	2.5		$	2.7		$	(2.1	)	$	(2.5	)

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	3.5		$	3.0		$	0.4		$	0.4
Interest Cost	6.1			6.3			1.7			1.8
Expected Return on Plan Assets	(8.6		)	(8.4		)	(3.1		)	(3.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(2.3		)	(2.4		)
Amortization of Net Actuarial Loss	2.4			2.5			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	3.4		$	3.5		$	(2.2	)	$	(2.5	)

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.9		$	1.6		$	0.2		$	0.2
Interest Cost	4.8			5.2			1.7			1.7
Expected Return on Plan Assets	(7.0		)	(6.9		)	(3.0		)	(3.2		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			1.1			0.9
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(1.7	)	$	(2.1	)

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	1.6		$	1.5		$	0.2		$	0.2
Interest Cost	2.7			2.8			0.8			0.8
Expected Return on Plan Assets	(3.9		)	(3.9		)	(1.4		)	(1.5		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.5			0.4
Net Periodic Benefit Cost (Credit)	$	1.5		$	1.6		$	(1.0	)	$	(1.2	)

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2017			2016			2017			2016
	(in millions)
Service Cost	$	2.2		$	2.0		$	0.2		$	0.2
Interest Cost	3.1			3.1			0.9			0.9
Expected Return on Plan Assets	(4.2		)	(4.1		)	(1.6		)	(1.7		)
Amortization of Prior Service Cost (Credit)	—			0.1			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.2			1.2			0.6			0.5
Net Periodic Benefit Cost (Credit)	$	2.3		$	2.3		$	(1.2	)	$	(1.4	)