Effects of Regulation (Tables)

12 Months Ended

Dec. 31, 2020

Regulated Generating Units to be Retired

Plant	Net Investment		Accelerated Depreciation Regulatory Asset		Cost of Removal Regulatory Liability			Projected Retirement Date	Current Authorized Recovery Period	Annual Depreciation (a)
	(dollars in millions)
Northeastern Plant, Unit 3	$	198.4	$	110.4	$	19.8	(b)	2026	(c)	$	14.9
Dolet Hills Power Station	74.4		71.2		24.0			2021	(d)	60.8
Pirkey Power Plant	199.5		12.2		38.7			2023	(e)	13.8
Welsh Plant, Units 1 and 3	549.8		3.6		57.6		(f)	2028	(g)	33.3

(a)Represents the amount of annual depreciation that has been collected from customers over the prior 12-month period.

(b)Includes Northeastern Plant, Unit 4, which was retired in 2016. Removal of Northeastern Plant, Unit 4, will be performed with Northeastern Plant, Unit 3, after retirement.

(c)Northeastern Plant, Unit 3 is currently being recovered through 2040.

(d)Dolet Hills Power Station is current being recovered through 2026 in the Louisiana jurisdiction and through 2046 in the Arkansas and Texas jurisdictions.

(e)Pirkey Power Plant is currently being recovered through 2025 in the Louisiana jurisdiction and through 2045 in the Arkansas and Texas jurisdictions.

(f)Includes Welsh Plant, Unit 2, which was retired in 2016. Removal of Welsh Plant, Unit 2, will be performed with Welsh Plant, Units 1 and 3, after retirement.

(g)Unit 1 is being recovered through 2027 in the Louisiana jurisdiction and through 2037 in the Arkansas and Texas jurisdictions. Unit 3 is being recovered through 2032 in the Louisiana jurisdiction and through 2042 in the Arkansas and Texas jurisdictions.

Regulatory Assets

	AEP
	December 31,				Remaining Recovery Period
	2020		2019
Current Regulatory Assets	(in millions)
Under-recovered Fuel Costs - earns a return	$	41.4	$	44.7	1 year
Under-recovered Fuel Costs - does not earn a return	49.3		48.2		1 year
Total Current Regulatory Assets	$	90.7	$	92.9
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Earning a Return
Dolet Hills Power Station Accelerated Depreciation	$	71.2	$	—
Kentucky Deferred Purchased Power Expenses	41.3		30.2
Plant Retirement Costs - Unrecovered Plant, Louisiana	35.2		35.2
Oklaunion Power Station Accelerated Depreciation	34.4		27.4
Other Regulatory Assets Pending Final Regulatory Approval	38.6		0.7
Total Regulatory Assets Currently Earning a Return	220.7		93.5
Regulatory Assets Currently Not Earning a Return
Storm-Related Costs	134.2		7.2
Plant Retirement Costs - Asset Retirement Obligation Costs	25.9		30.1
COVID-19	24.9		—
Vegetation Management Program - AEP Texas	3.8		29.4
Other Regulatory Assets Pending Final Regulatory Approval	32.7		21.5
Total Regulatory Assets Currently Not Earning a Return	221.5		88.2
Total Regulatory Assets Pending Final Regulatory Approval	442.2		181.7
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Plant Retirement Costs - Unrecovered Plant (a)	713.1		690.5		23 years
Plant Retirement Costs - Asset Retirement Obligation Costs	107.1		87.4		20 years
Meter Replacement Costs	55.5		65.4		7 years
Ohio Distribution Decoupling	46.6		31.4		2 years
Environmental Control Projects	38.6		41.0		20 years
Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction	34.4		13.5		8 years
Cook Plant Uprate Project	30.2		32.6		13 years
Storm-Related Costs	11.5		21.3		2 years
Advanced Metering System	—		26.5
Other Regulatory Assets Approved for Recovery	94.4		79.6		various
Total Regulatory Assets Currently Earning a Return	1,131.4		1,089.2
Regulatory Assets Currently Not Earning a Return
Pension and OPEB Funded Status	1,088.6		1,309.8		12 years
Plant Retirement Costs - Asset Retirement Obligation Costs	212.7		28.8		22 years
Unamortized Loss on Reacquired Debt	120.0		129.0		28 years
Unrealized Loss on Forward Commitments	111.3		106.8		12 years
Vegetation Management	67.8		43.6		5 years
Cook Plant Nuclear Refueling Outage Levelization	39.5		63.8		2 years
PJM/SPP Annual Formula Rate True-up	33.0		7.3		2 years
Postemployment Benefits	29.1		34.2		3 years
OVEC Purchased Power	27.4		1.5		2 years
Fuel and Purchased Power Adjustment Rider	24.0		7.1		2 years
Medicare Subsidy	18.6		23.2		4 years
Other Regulatory Assets Approved for Recovery	181.4		132.8		various
Total Regulatory Assets Currently Not Earning a Return	1,953.4		1,887.9
Total Regulatory Assets Approved for Recovery	3,084.8		2,977.1
Total Noncurrent Regulatory Assets	$	3,527.0	$	3,158.8

(a)Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information.

	AEP Texas
	December 31,				Remaining Recovery Period
Regulatory Assets:	2020		2019
	(in millions)
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Earning a Return
Advanced Metering System	$	16.3	$	—
Total Regulatory Assets Currently Earning a Return	16.3		—
Regulatory Assets Currently Not Earning a Return
COVID-19	10.5		—
Vegetation Management Program	3.8		29.4
Other Regulatory Assets Pending Final Regulatory Approval	2.3		1.4
Total Regulatory Assets Currently Not Earning a Return	16.6		30.8
Total Regulatory Assets Pending Final Regulatory Approval	32.9		30.8
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Meter Replacement Costs	29.3		35.2		6 years
Advanced Metering System	—		26.5
Total Regulatory Assets Currently Earning a Return	29.3		61.7
Regulatory Assets Currently Not Earning a Return
Pension and OPEB Funded Status	145.0		172.0		12 years
Vegetation Management Program	22.4		—		5 years
Storm-Related Costs	17.1		—		4 years
Peak Demand Reduction/Energy Efficiency	7.7		3.5		2 years
Other Regulatory Assets Approved for Recovery	12.4		12.6		various
Total Regulatory Assets Currently Not Earning a Return	204.6		188.1
Total Regulatory Assets Approved for Recovery	233.9		249.8
Total Noncurrent Regulatory Assets	$	266.8	$	280.6

	AEPTCo
	December 31,				Remaining Recovery Period
Regulatory Assets:	2020		2019
	(in millions)
Noncurrent Regulatory Assets
Regulatory assets approved for recovery:
Regulatory Assets Currently Not Earning a Return
PJM/SPP Annual Formula Rate True-up	$	15.1	$	4.2	2 years
Total Regulatory Assets Approved for Recovery	15.1		4.2
Total Noncurrent Regulatory Assets	$	15.1	$	4.2

	APCo
	December 31,				Remaining Recovery Period
Regulatory Assets:	2020		2019
	(in millions)
Current Regulatory Assets
Under-recovered Fuel Costs, Virginia - earns a return	$	3.3	$	36.8	1 year
Under-recovered Fuel Costs - does not earn a return	2.0		5.7		1 year
Total Current Regulatory Assets	$	5.3	$	42.5
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Earning a Return
COVID-19 - Virginia	$	3.7	$	—
Plant Retirement Costs - Materials and Supplies	—		0.5
Total Regulatory Assets Currently Earning a Return	3.7		0.5
Regulatory Assets Currently Not Earning a Return
Plant Retirement Costs - Asset Retirement Obligation Costs	25.9		30.1
Environmental Expense Deferral - Virginia	9.3		—
COVID-19 - West Virginia	1.5		—
Other Regulatory Assets Pending Final Regulatory Approval	3.4		—
Total Regulatory Assets Currently Not Earning a Return	40.1		30.1
Total Regulatory Assets Pending Final Regulatory Approval	43.8		30.6
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Plant Retirement Costs - Unrecovered Plant (a)	122.4		86.4		23 years
Other Regulatory Assets Approved for Recovery	1.0		0.5		various
Total Regulatory Assets Currently Earning a Return	123.4		86.9
Regulatory Assets Currently Not Earning a Return
Plant Retirement Costs - Asset Retirement Obligation Costs	202.7		—		15 years
Pension and OPEB Funded Status	114.4		160.8		12 years
Unamortized Loss on Reacquired Debt	82.1		85.5		25 years
Vegetation Management Program - West Virginia	45.4		43.6		2 years
Virginia Transmission Rate Adjustment Clause	18.8		—		2 years
Peak Demand Reduction/Energy Efficiency	16.8		19.5		6 years
Postemployment Benefits	13.5		15.9		3 years
PJM Annual Formula Rate True-up	12.7		—		2 years
Other Regulatory Assets Approved for Recovery	12.7		14.4		various
Total Regulatory Assets Currently Not Earning a Return	519.1		339.7
Total Regulatory Assets Approved for Recovery	642.5		426.6
Total Noncurrent Regulatory Assets	$	686.3	$	457.2

(a)December 31, 2020 amount includes Virginia and West Virginia jurisdictions. December 31, 2019 amount includes West Virginia jurisdiction.

	I&M
	December 31,				Remaining Recovery Period
Regulatory Assets:	2020		2019
	(in millions)
Current Regulatory Assets
Under-recovered Fuel Costs - earns a return	$	5.4	$	3.0	1 year
Total Current Regulatory Assets	$	5.4	$	3.0
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Earning a Return
Other Regulatory Assets Pending Final Regulatory Approval	$	0.5	$	—
Total Regulatory Assets Currently Earning a Return	0.5		—
Regulatory Assets Currently Not Earning a Return
COVID-19	3.8		—
Cook Plant Study Costs	—		7.6
Other Regulatory Assets Pending Final Regulatory Approval	—		0.1
Total Regulatory Assets Currently Not Earning a Return	3.8		7.7
Total Regulatory Assets Pending Final Regulatory Approval	4.3		7.7
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Plant Retirement Costs - Unrecovered Plant	191.5		214.9		8 years
Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction	34.4		13.5		8 years
Cook Plant Uprate Project	30.2		32.6		13 years
Deferred Cook Plant Life Cycle Management Project Costs	14.1		15.1		14 years
Cook Plant Turbine	11.1		13.4		18 years
Cook Plant Study Costs - Indiana	10.1		—		15 years
Other Regulatory Assets Approved for Recovery	7.0		6.9		various
Total Regulatory Assets Currently Earning a Return	298.4		296.4
Regulatory Assets Currently Not Earning a Return
Cook Plant Nuclear Refueling Outage Levelization	39.5		63.8		2 years
Pension and OPEB Funded Status	25.7		67.5		12 years
Unamortized Loss on Reacquired Debt	15.7		17.2		28 years
Postemployment Benefits	4.9		7.2		3 years
Other Regulatory Assets Approved for Recovery	16.3		22.3		various
Total Regulatory Assets Currently Not Earning a Return	102.1		178.0
Total Regulatory Assets Approved for Recovery	400.5		474.4
Total Noncurrent Regulatory Assets	$	404.8	$	482.1

	OPCo
	December 31,				Remaining Recovery Period
Regulatory Assets:	2020		2019
	(in millions)
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Not Earning a Return
COVID-19	$	4.4	$	—
Storm-Related Costs	4.0		—
Other Regulatory Assets Pending Final Regulatory Approval	—		0.1
Total Regulatory Assets Pending Final Regulatory Approval	8.4		0.1
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Ohio Distribution Decoupling	46.6		31.4		2 years
Ohio Basic Transmission Cost Rider	12.3		—		2 years
Other Regulatory Assets Approved for Recovery	1.3		—		various
Total Regulatory Assets Currently Earning a Return	60.2		31.4
Regulatory Assets Currently Not Earning a Return
Pension and OPEB Funded Status	130.7		167.3		12 years
Unrealized Loss on Forward Commitments	110.0		103.6		12 years
OVEC Purchased Power	27.4		1.5		2 years
Smart Grid Costs	19.2		13.7		2 years
Distribution Investment Rider	7.4		10.9		2 years
Postemployment Benefits	6.7		7.6		3 years
Other Regulatory Assets Approved for Recovery	15.8		15.7		various
Total Regulatory Assets Currently Not Earning a Return	317.2		320.3
Total Regulatory Assets Approved for Recovery	377.4		351.7
Total Noncurrent Regulatory Assets	$	385.8	$	351.8

	PSO
	December 31,				Remaining Recovery Period
	2020		2019
Regulatory Assets:	(in millions)
Current Regulatory Assets
Under-recovered Fuel Costs - earns a return	$	30.1	$	—	1 year
Total Current Regulatory Assets	$	30.1	$	—
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Earning a Return
Oklaunion Power Station Accelerated Depreciation	$	34.4	$	27.4
Total Regulatory Assets Currently Earning a Return	34.4		27.4
Regulatory Assets Currently Not Earning a Return
Storm-Related Costs	15.8		7.2
COVID-19	0.3		—
Total Regulatory Assets Currently Not Earning a Return	16.1		7.2
Total Regulatory Assets Pending Final Regulatory Approval	50.5		34.6
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Plant Retirement Costs - Unrecovered Plant (a)	180.8		167.0		20 years
Environmental Control Projects	26.5		27.8		20 years
Meter Replacement Costs	26.2		30.2		7 years
Storm-Related Costs	11.5		21.3		2 years
Red Rock Generating Facility	8.2		8.4		36 years
Other Regulatory Assets Approved for Recovery	0.5		0.6		various
Total Regulatory Assets Currently Earning a Return	253.7		255.3
Regulatory Assets Currently Not Earning a Return
Pension and OPEB Funded Status	52.3		73.4		12 years
Unamortized Loss on Reacquired Debt	6.1		6.5		18 years
Other Regulatory Assets Approved for Recovery	12.4		5.4		various
Total Regulatory Assets Currently Not Earning a Return	70.8		85.3
Total Regulatory Assets Approved for Recovery	324.5		340.6
Total Noncurrent Regulatory Assets	$	375.0	$	375.2

(a)Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information.

	SWEPCo
	December 31,				Remaining Recovery Period
	2020		2019
Regulatory Assets:	(in millions)
Current Regulatory Assets
Under-recovered Fuel Costs - earns a return (a)	$	2.6	$	4.9	1 year
Total Current Regulatory Assets	$	2.6	$	4.9
Noncurrent Regulatory Assets
Regulatory assets pending final regulatory approval:
Regulatory Assets Currently Earning a Return
Dolet Hills Power Station Accelerated Depreciation	$	71.2	$	—
Plant Retirement Costs - Unrecovered Plant, Louisiana	35.2		35.2
Pirkey Power Plant Accelerated Depreciation	12.2		—
Welsh Plant, Units 1 and 3 Accelerated Depreciation	3.6		—
Other Regulatory Assets Pending Final Regulatory Approval	2.2		0.2
Total Regulatory Assets Currently Earning a Return	124.4		35.4
Regulatory Assets Currently Not Earning a Return
Storm-Related Costs	99.3		—
Asset Retirement Obligation - Louisiana	9.1		7.2
Other Regulatory Assets Pending Final Regulatory Approval	14.5		3.7
Total Regulatory Assets Currently Not Earning a Return	122.9		10.9
Total Regulatory Assets Pending Final Regulatory Approval	247.3		46.3
Regulatory assets approved for recovery:
Regulatory Assets Currently Earning a Return
Plant Retirement Costs - Unrecovered Plant, Arkansas	14.4		15.1		22 years
Environmental Controls Projects	12.1		13.2		12 years
Other Regulatory Assets Approved for Recovery	7.1		8.9		various
Total Regulatory Assets Currently Earning a Return	33.6		37.2
Regulatory Assets Currently Not Earning a Return
Pension and OPEB Funded Status	89.1		102.6		12 years
Plant Retirement Costs - Unrecovered Plant, Texas	16.1		16.6		21 years
Other Regulatory Assets Approved for Recovery	17.0		19.7		various
Total Regulatory Assets Currently Not Earning a Return	122.2		138.9
Total Regulatory Assets Approved for Recovery	155.8		176.1
Total Noncurrent Regulatory Assets	$	403.1	$	222.4

(a)December 31, 2020 amount includes Louisiana jurisdiction. December 31, 2019 amount includes Arkansas jurisdiction.

Regulatory Liabilities

	AEP Texas
	December 31,				Remaining Refund Period
Regulatory Liabilities:	2020		2019
	(in millions)
Noncurrent Regulatory Liabilities and
Deferred Investment Tax Credits
Regulatory liabilities pending final regulatory determination:
Regulatory Liabilities Currently Paying a Return
Other Regulatory Liabilities Pending Final Regulatory Determination	$	2.5	$	—
Total Regulatory Liabilities Currently Paying a Return	2.5		—
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	—		274.9
Excess ADIT that is Not Subject to Rate Normalization Requirements	(8.2)		87.1
Total Income Tax Related Regulatory Liabilities	(8.2)		362.0
Total Regulatory Liabilities Pending Final Regulatory Determination	(5.7)		362.0
Regulatory liabilities approved for payment:
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	718.3		689.6		(b)
Other Regulatory Liabilities Approved for Payment	5.3		10.1		various
Total Regulatory Liabilities Currently Paying a Return	723.6		699.7
Regulatory Liabilities Currently Not Paying a Return
Transition and Restoration Charges	48.2		50.5		9 years
Deferred Investment Tax Credits	8.5		9.6		20 years
Other Regulatory Liabilities Approved for Payment	1.2		4.8		various
Total Regulatory Liabilities Currently Not Paying a Return	57.9		64.9
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	506.0		236.5		(c)
Excess ADIT that is Not Subject to Rate Normalization Requirements	41.7		—		1 years
Income Taxes Subject to Flow Through	(52.7)		(46.2)		28 years
Total Income Tax Related Regulatory Liabilities	495.0		190.3
Total Regulatory Liabilities Approved for Payment	1,276.5		954.9
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$	1,270.8	$	1,316.9

(a)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base.

(b)Relieved as removal costs are incurred.

(c)Refunded using ARAM.

	AEPTCo
	December 31,				Remaining Refund Period
Regulatory Liabilities:	2020		2019
	(in millions)
Noncurrent Regulatory Liabilities
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	$	198.6	$	141.0	(b)
Total Regulatory Liabilities Currently Paying a Return	198.6		141.0
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	531.5		535.7		(c)
Excess ADIT that is Not Subject to Rate Normalization Requirements	(30.6)		(35.4)		8 years
Income Taxes Subject to Flow Through	(117.7)		(100.4)		38 years
Total Income Tax Related Regulatory Liabilities	383.2		399.9
Total Regulatory Liabilities Approved for Payment	581.8		540.9
Total Noncurrent Regulatory Liabilities	$	581.8	$	540.9

(a)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. 

(b)Relieved as removal costs are incurred.

(c)Refunded using ARAM.

	APCo
	December 31,				Remaining Refund Period
Regulatory Liabilities:	2020		2019
	(in millions)
Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits
Regulatory liabilities approved for payment:
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	$	678.9	$	635.3	(b)
Deferred Investment Tax Credits	0.3		0.5		33 years
Total Regulatory Liabilities Currently Paying a Return	679.2		635.8
Regulatory Liabilities Currently Not Paying a Return
2017-2019 Virginia Triennial Revenue Provision	44.2		—		28 years
PJM Transmission Enhancement Refund	16.3		19.5		5 years
Virginia Transmission Rate Adjustment Clause	—		28.1
Other Regulatory Liabilities Approved for Payment	12.3		18.0		various
Total Regulatory Liabilities Currently Not Paying a Return	72.8		65.6
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	690.0		718.9		(c)
Excess ADIT that is Not Subject to Rate Normalization Requirements	139.1		210.7		8 years
Income Taxes Subject to Flow Through	(356.4)		(362.3)		24 years
Total Income Tax Related Regulatory Liabilities	472.7		567.3
Total Regulatory Liabilities Approved for Payment	1,224.7		1,268.7
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$	1,224.7	$	1,268.7

(a)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base.

(b)Relieved as removal costs are incurred.

(c)Refunded using ARAM.

	I&M
	December 31,				Remaining Refund Period
Regulatory Liabilities:	2020		2019
	(in millions)
Current Regulatory Liabilities
Over-recovered Fuel Costs, Indiana - does not pay a return	$	20.8	$	6.1	1 year
Total Current Regulatory Liabilities	$	20.8	$	6.1
Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits
Regulatory liabilities approved for payment:
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	$	168.2	$	166.7	(b)
Other Regulatory Liabilities Approved for Payment	17.4		0.3		various
Total Regulatory Liabilities Currently Paying a Return	185.6		167.0
Regulatory Liabilities Currently Not Paying a Return
Excess Nuclear Decommissioning Funding	1,476.6		1,236.0		(c)
Spent Nuclear Fuel	43.1		43.6		(c)
Deferred Investment Tax Credits	21.3		25.8		19 years
PJM Costs and Off-system Sales Margin Sharing - Indiana	13.3		17.0		2 years
PJM Transmission Enhancement Refund	9.9		11.8		5 years
Deferred Gain on Sale of Rockport Unit 2	7.2		10.9		2 years
Other Regulatory Liabilities Approved for Payment	30.1		24.9		various
Total Regulatory Liabilities Currently Not Paying a Return	1,601.5		1,370.0
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	450.6		470.9		(d)
Excess ADIT that is Not Subject to Rate Normalization Requirements	136.2		184.5		4 years
Income Taxes Subject to Flow Through	(332.0)		(301.0)		20 years
Total Income Tax Related Regulatory Liabilities	254.8		354.4
Total Regulatory Liabilities Approved for Payment	2,041.9		1,891.4
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$	2,041.9	$	1,891.4

(a)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base.

(b)Relieved as removal costs are incurred.

(c)Relieved when plant is decommissioned.

(d)Refunded using ARAM.

	OPCo
	December 31,				Remaining Refund Period
	2020		2019
Regulatory Liabilities:	(in millions)
Current Regulatory Liabilities
Over-recovered Fuel Costs - does not pay a return	$	3.9	$	2.8	1 year
Total Current Regulatory Liabilities	$	3.9	$	2.8
Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits
Regulatory liabilities pending final regulatory determination:
Regulatory Liabilities Currently Not Paying a Return
Other Regulatory Liabilities Pending Final Regulatory Determination	$	0.2	$	0.2
Total Regulatory Liabilities Pending Final Regulatory Determination	0.2		0.2
Regulatory liabilities approved for payment:
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	458.4		446.3		(b)
Ohio Basic Transmission Cost Rider	—		37.2
Other Regulatory Liabilities Approved for Payment	—		1.3
Total Regulatory Liabilities Currently Paying a Return	458.4		484.8
Regulatory Liabilities Currently Not Paying a Return
PJM Transmission Enhancement Refund	24.5		29.4		5 years
Peak Demand Reduction/Energy Efficiency	19.9		19.7		2 years
Ohio Enhanced Service Reliability Plan	5.7		29.7		2 years
Other Regulatory Liabilities Approved for Payment	0.7		2.9		various
Total Regulatory Liabilities Currently Not Paying a Return	50.8		81.7
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	334.6		341.6		(c)
Excess ADIT that is Not Subject to Rate Normalization Requirements	223.9		252.3		8 years
Income Taxes Subject to Flow Through	(62.7)		(69.7)		29 years
Total Income Tax Related Regulatory Liabilities	495.8		524.2
Total Regulatory Liabilities Approved for Payment	1,005.0		1,090.7
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$	1,005.2	$	1,090.9

(a)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base.

(b)Relieved as removal costs are incurred.

(c)Refunded using ARAM.

	PSO
	December 31,				Remaining Refund Period
	2020		2019
Regulatory Liabilities:	(in millions)
Current Regulatory Liabilities
Over-recovered Fuel Costs - pays a return	$	—	$	63.9
Total Current Regulatory Liabilities	$	—	$	63.9
Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits
Regulatory liabilities approved for payment:
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	$	289.9	$	286.8	(b)
Total Regulatory Liabilities Currently Paying a Return	289.9		286.8
Regulatory Liabilities Currently Not Paying a Return
Deferred Investment Tax Credits	51.0		51.5		24 years
Other Regulatory Liabilities Approved for Payment	1.3		4.7		various
Total Regulatory Liabilities Currently Not Paying a Return	52.3		56.2
Income Tax Related Regulatory Liabilities (a)
Excess ADIT Associated with Certain Depreciable Property	397.0		405.8		(c)
Excess ADIT that is Not Subject to Rate Normalization Requirements	71.3		96.3		4 years
Income Taxes Subject to Flow Through	(8.3)		(7.9)		27 years
Total Income Tax Related Regulatory Liabilities	460.0		494.2
Total Regulatory Liabilities Approved for Payment	802.2		837.2
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$	802.2	$	837.2

(a)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base.

(b)Relieved as removal costs are incurred.

(c)Refunded using ARAM.

	SWEPCo
	December 31,				Remaining Refund Period
	2020		2019
Regulatory Liabilities:	(in millions)
Current Regulatory Liabilities
Over-recovered Fuel Costs - pays a return (a)	$	37.6	$	13.6	1 year
Total Current Regulatory Liabilities	$	37.6	$	13.6
Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits
Regulatory liabilities pending final regulatory determination:
Income Tax Related Regulatory Liabilities (b)
Excess ADIT Associated with Certain Depreciable Property	$	291.6	$	297.0
Excess ADIT that is Not Subject to Rate Normalization Requirements	21.8		22.7
Total Regulatory Liabilities Pending Final Regulatory Determination	313.4		319.7
Regulatory liabilities approved for payment:
Regulatory Liabilities Currently Paying a Return
Asset Removal Costs	470.9		453.4		(c)
Other Regulatory Liabilities Approved for Payment	2.4		2.8		various
Total Regulatory Liabilities Currently Paying a Return	473.3		456.2
Regulatory Liabilities Currently Not Paying a Return
Peak Demand Reduction/Energy Efficiency	5.2		6.0		2 years
Deferred Investment Tax Credits	1.8		3.1		10 years
Other Regulatory Liabilities Approved for Payment	1.2		1.7		various
Total Regulatory Liabilities Currently Not Paying a Return	8.2		10.8
Income Tax Related Regulatory Liabilities (b)
Excess ADIT Associated with Certain Depreciable Property	332.5		339.4		(d)
Excess ADIT that is Not Subject to Rate Normalization Requirements	11.5		27.8		(e)
Income Taxes Subject to Flow Through	(275.5)		(261.6)		28 years
Total Income Tax Related Regulatory Liabilities	68.5		105.6
Total Regulatory Liabilities Approved for Payment	550.0		572.6
Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits	$	863.4	$	892.3

(a)December 31, 2020 amount includes Arkansas and Texas jurisdictions. December 31, 2019 amount includes Texas and Louisiana jurisdictions.

(b)This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform.  The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base.

(c)Relieved as removal costs are incurred.

(d)Refunded using ARAM.

(e)Current balance represents revisions to balances for jurisdictions having previously issued orders on treatment for refund, refund period to be addressed in future proceedings.