FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Schedule of Book Values and Fair Values of Long-term Debt

The book values and fair values of Long-term Debt are summarized in the following table:

	March 31, 2026				December 31, 2025
Company	Book Value		Fair Value		Book Value		Fair Value
	(in millions)
AEP	$	49,554	$	46,612	$	47,322	$	44,930
AEP Texas	7,744		7,221		7,016		6,586
AEPTCo	6,613		5,750		6,599		5,812
APCo	6,247		6,053		6,259		6,147
I&M	4,174		3,847		3,561		3,288
OPCo	3,719		3,289		3,718		3,331
PSO	3,526		3,307		3,526		3,349
SWEPCo	4,858		4,449		4,974		4,603

Schedule of Available-For-Sale Securities

The following is a summary of Other Temporary Investments and Restricted Cash:

	March 31, 2026
			Gross		Gross
			Unrealized		Unrealized		Fair
Other Temporary Investments and Restricted Cash	Cost		Gains		Losses		Value
	(in millions)
Restricted Cash (a)	$	33	$	—	$	—	$	33
Other Cash Deposits	11		—		—		11
Fixed Income Securities – Mutual Funds (b)	164		—		(3)		161
Equity Securities – Mutual Funds	11		27		—		38
Total Other Temporary Investments and Restricted Cash	$	219	$	27	$	(3)	$	243

	December 31, 2025
			Gross		Gross
			Unrealized		Unrealized		Fair
Other Temporary Investments and Restricted Cash	Cost		Gains		Losses		Value
	(in millions)
Restricted Cash (a)	$	71	$	—	$	—	$	71
Other Cash Deposits	13		—		—		13
Fixed Income Securities – Mutual Funds (b)	167		—		(2)		165
Equity Securities – Mutual Funds	13		29		—		42
Total Other Temporary Investments and Restricted Cash	$	264	$	29	$	(2)	$	291

(a)Primarily represents amounts held for the repayment of debt.

(b)Primarily short and intermediate maturities which may be sold and do not contain maturity dates.

The following is a summary of nuclear trust fund investments:

	March 31, 2026								December 31, 2025
			Gross		Gross		Other-Than-				Gross		Gross		Other-Than-
	Fair		Unrealized		Unrealized		Temporary		Fair		Unrealized		Unrealized		Temporary
	Value		Gains		Losses		Impairments		Value		Gains		Losses		Impairments
	(in millions)
Cash and Cash Equivalents	$	27	$	—	$	—	$	—	$	29	$	—	$	—	$	—
Fixed Income Securities:
United States Government	1,351		13		(2)		(16)		1,351		22		(1)		(15)
Corporate Debt	379		3		(10)		(6)		376		6		(7)		(6)
Subtotal Fixed Income Securities	1,730		16		(12)		(22)		1,727		28		(8)		(21)
Equity Securities - Domestic	3,046		2,498		(2)		—		3,160		2,621		(1)		—
Spent Nuclear Fuel and Decommissioning Trusts	$	4,803	$	2,514	$	(14)	$	(22)	$	4,916	$	2,649	$	(9)	$	(21)

Schedule of Fixed Income And Equity Securities Activity

The following table provides the activity for fixed income and equity securities within Other Temporary Investments:

	Three Months Ended March 31,
	2026		2025
	(in millions)
Proceeds from Investment Sales	$	7	$	10
Purchases of Investments	2		2
Gross Realized Gains on Investment Sales	1		4
Gross Realized Losses on Investment Sales	—		—

Schedule of Securities Activity

The following table provides the securities activity within the decommissioning and SNF trusts:

	Three Months Ended March 31,
	2026		2025
	(in millions)
Proceeds from Investment Sales	$	548	$	577
Purchases of Investments	573		601
Gross Realized Gains on Investment Sales	5		2
Gross Realized Losses on Investment Sales	4		1

Schedule of Contractual Maturities, Fair Value of Debt Securities

The fair value of fixed income securities held in the nuclear trust funds, summarized by contractual maturities, as of March 31, 2026 was as follows:

	Fair Value of Fixed
	Income Securities
	(in millions)
Within 1 year	$	379
After 1 year through 5 years	731
After 5 years through 10 years	251
After 10 years	369
Total	$	1,730

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following tables set forth, by level within the fair value hierarchy, the Registrants’ financial assets and liabilities that were accounted for at fair value on a recurring basis.  As required by the accounting guidance for “Fair Value Measurements and Disclosures,” financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.  Management’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels.  There have not been any significant changes in management’s valuation techniques.

AEP

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Other Temporary Investments and Restricted Cash
Restricted Cash	$	25	$	—	$	—	$	8	$	33
Other Cash Deposits (a)	—		—		—		11		11
Fixed Income Securities – Mutual Funds	161		—		—		—		161
Equity Securities – Mutual Funds (b)	38		—		—		—		38
Total Other Temporary Investments and Restricted Cash	224		—		—		19		243
Risk Management Assets
Risk Management Commodity Contracts (c) (d)	2		958		259		(841)		378
Cash Flow Hedges:
Commodity Hedges (c)	—		96		17		(12)		101
Total Risk Management Assets	2		1,054		276		(853)		479
Spent Nuclear Fuel and Decommissioning Trusts
Cash and Cash Equivalents (e)	13		—		—		14		27
Fixed Income Securities:
United States Government	—		1,351		—		—		1,351
Corporate Debt	—		379		—		—		379
Subtotal Fixed Income Securities	—		1,730		—		—		1,730
Equity Securities – Domestic (b)	3,046		—		—		—		3,046
Total Spent Nuclear Fuel and Decommissioning Trusts	3,059		1,730		—		14		4,803
Total Assets	$	3,285	$	2,784	$	276	$	(820)	$	5,525
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c) (d)	$	8	$	887	$	142	$	(797)	$	240
Cash Flow Hedges:
Commodity Hedges (c)	—		31		2		(11)		22
Fair Value Hedges	—		33		—		—		33
Total Risk Management Liabilities	$	8	$	951	$	144	$	(808)	$	295

Assets and Liabilities Measured at Fair Value on a Recurring Basis

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Other Temporary Investments and Restricted Cash
Restricted Cash	$	48	$	—	$	—	$	23	$	71
Other Cash Deposits (a)	—		—		—		13		13
Fixed Income Securities – Mutual Funds	165		—		—		—		165
Equity Securities – Mutual Funds (b)	42		—		—		—		42
Total Other Temporary Investments and Restricted Cash	255		—		—		36		291
Risk Management Assets
Risk Management Commodity Contracts (c) (f)	2		831		393		(713)		513
Cash Flow Hedges:
Commodity Hedges (c)	—		100		18		(14)		104
Total Risk Management Assets	2		931		411		(727)		617
Spent Nuclear Fuel and Decommissioning Trusts
Cash and Cash Equivalents (e)	14		—		—		15		29
Fixed Income Securities:
United States Government	—		1,351		—		—		1,351
Corporate Debt	—		376		—		—		376
Subtotal Fixed Income Securities	—		1,727		—		—		1,727
Equity Securities – Domestic (b)	3,160		—		—		—		3,160
Total Spent Nuclear Fuel and Decommissioning Trusts	3,174		1,727		—		15		4,916
Total Assets	$	3,431	$	2,658	$	411	$	(676)	$	5,824
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c) (f)	$	4	$	752	$	151	$	(633)	$	274
Cash Flow Hedges:
Commodity Hedges (c)	—		19		1		(14)		6
Fair Value Hedges	—		30		—		—		30
Total Risk Management Liabilities	$	4	$	801	$	152	$	(647)	$	310

AEP Texas

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Restricted Cash for Securitized Funding	$	6	$	—	$	—	$	—	$	6
Risk Management Assets
Risk Management Commodity Contracts (c)	—		1		—		(1)		—
Total Assets	$	6	$	1	$	—	$	(1)	$	6

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Restricted Cash for Securitized Funding	$	14	$	—	$	—	$	—	$	14

APCo

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Restricted Cash for Securitized Funding	$	12	$	—	$	—	$	—	$	12
Risk Management Assets
Risk Management Commodity Contracts (c)	—		4		22		(4)		22
Total Assets	$	12	$	4	$	22	$	(4)	$	34
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	9	$	1	$	(3)	$	7

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Restricted Cash for Securitized Funding	$	18	$	—	$	—	$	—	$	18
Risk Management Assets
Risk Management Commodity Contracts (c)	—		3		81		(2)		82
Total Assets	$	18	$	3	$	81	$	(2)	$	100
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	6	$	—	$	(3)	$	3

I&M

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Risk Management Assets
Risk Management Commodity Contracts (c)	$	—	$	12	$	3	$	(12)	$	3
Spent Nuclear Fuel and Decommissioning Trusts
Cash and Cash Equivalents (e)	13		—		—		14		27
Fixed Income Securities:
United States Government	—		1,351		—		—		1,351
Corporate Debt	—		379		—		—		379
Subtotal Fixed Income Securities	—		1,730		—		—		1,730
Equity Securities - Domestic (b)	3,046		—		—		—		3,046
Total Spent Nuclear Fuel and Decommissioning Trusts	3,059		1,730		—		14		4,803
Total Assets	$	3,059	$	1,742	$	3	$	2	$	4,806
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	16	$	1	$	(17)	$	—

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Risk Management Assets
Risk Management Commodity Contracts (c)	$	—	$	12	$	9	$	(11)	$	10
Spent Nuclear Fuel and Decommissioning Trusts
Cash and Cash Equivalents (e)	14		—		—		15		29
Fixed Income Securities:
United States Government	—		1,351		—		—		1,351
Corporate Debt	—		376		—		—		376
Subtotal Fixed Income Securities	—		1,727		—		—		1,727
Equity Securities - Domestic (b)	3,160		—		—		—		3,160
Total Spent Nuclear Fuel and Decommissioning Trusts	3,174		1,727		—		15		4,916
Total Assets	$	3,174	$	1,739	$	9	$	4	$	4,926
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	11	$	—	$	(11)	$	—

OPCo

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Risk Management Assets
Risk Management Commodity Contracts (c)	$	—	$	1	$	—	$	(1)	$	—
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	—	$	32	$	—	$	32

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Liabilities:	(in millions)
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	—	$	33	$	—	$	33

PSO

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Risk Management Assets
Risk Management Commodity Contracts (c)	$	—	$	1	$	21	$	(1)	$	21
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	35	$	—	$	—	$	35

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Risk Management Assets
Risk Management Commodity Contracts (c)	$	—	$	1	$	43	$	(2)	$	42
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	28	$	2	$	(2)	$	28

SWEPCo

Assets and Liabilities Measured at Fair Value on a Recurring Basis

March 31, 2026

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Restricted Cash for Securitized Funding	$	7	$	—	$	—	$	—	$	7
Risk Management Assets
Risk Management Commodity Contracts (c)	—		1		16		(2)		15
Total Assets	$	7	$	1	$	16	$	(2)	$	22
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	13	$	1	$	(1)	$	13

December 31, 2025

	Level 1		Level 2		Level 3		Other		Total
Assets:	(in millions)
Restricted Cash for Securitized Funding	$	15	$	—	$	—	$	—	$	15
Risk Management Assets
Risk Management Commodity Contracts (c)	—		—		37		(2)		35
Total Assets	$	15	$	—	$	37	$	(2)	$	50
Liabilities:
Risk Management Liabilities
Risk Management Commodity Contracts (c)	$	—	$	11	$	2	$	(2)	$	11

(a)Amounts in “Other’’ column primarily represent cash deposits in bank accounts with financial institutions or third-parties.  Level 1 and Level 2 amounts primarily represent investments in money market funds.

(b)Amounts represent publicly traded equity securities and equity-based mutual funds.

(c)Amounts in “Other’’ column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.’’

(d)The March 31, 2026 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $(6) million in 2026; Level 2 matures $71 million in periods 2027-2029; Level 3 matures $84 million in 2026, $50 million in periods 2027-2029, $(4) million in periods 2030-2031 and $(14) million in periods 2032-2035.  Risk management commodity contracts are substantially comprised of power contracts.

(e)Amounts in “Other’’ column primarily represent accrued interest receivables from financial institutions.  Level 1 amounts primarily represent investments in money market funds.

(f)The December 31, 2025 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $(2) million in 2026; Level 2 matures $12 million in 2026, $65 million in periods 2027-2029, and $1 million in periods 2030-2031; Level 3 matures $210 million in 2026, $51 million in periods 2027-2029, $(6) million in periods 2030-2031 and $(13) million in periods 2032-2034.  Risk management commodity contracts are substantially comprised of power contracts.

Schedule of Changes in Fair Value of Net Trading Derivatives Classified as Level 3

The following tables set forth a reconciliation of changes in the fair value of net trading derivatives classified as Level 3 in the fair value hierarchy:

Three Months Ended March 31, 2026	AEP		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Balance as of December 31, 2025	$	259	$	81	$	9	$	(33)	$	41	$	35
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b)	175		109		7		1		36		7
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a)	(4)		—		—		—		—		—
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c)	8		—		—		—		—		—
Settlements	(319)		(172)		(13)		1		(61)		(29)
Transfers into Level 3 (d) (e)	2		—		—		—		—		—
Transfers out of Level 3 (e)	1		—		—		—		—		—
Changes in Fair Value Allocated to Regulated Jurisdictions (f)	10		3		(1)		(1)		5		2
Balance as of March 31, 2026	$	132	$	21	$	2	$	(32)	$	21	$	15

Three Months Ended March 31, 2025	AEP		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Balance as of December 31, 2024	$	166	$	35	$	6	$	(47)	$	20	$	17
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b)	92		40		9		—		17		21
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a)	19		—		—		—		—		—
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c)	5		—		—		—		—		—
Settlements	(168)		(66)		(12)		2		(28)		(31)
Transfers into Level 3 (d) (e)	1		—		—		—		—		—
Transfers out of Level 3 (e)	1		—		—		—		—		—
Changes in Fair Value Allocated to Regulated Jurisdictions (f)	7		(1)		1		(6)		6		6
Balance as of March 31, 2025	$	123	$	8	$	4	$	(51)	$	15	$	13

(a)Included in revenues on the statements of income.

(b)Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract.

(c)Included in cash flow hedges on the statements of comprehensive income.

(d)Represents existing assets or liabilities that were previously categorized as Level 2.

(e)Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred.

(f)Relates to the net gains (losses) of those contracts that are not reflected on the statements of income.  These changes in fair value are recorded as regulatory liabilities for net gains and as regulatory assets for net losses or accounts payable.

Schedule of Significant Unobservable Inputs for Level 3

The following tables quantify the significant unobservable inputs used in developing the fair value of Level 3 positions:

Significant Unobservable Inputs

March 31, 2026

							Significant	Input/Range
	Type of	Fair Value				Valuation	Unobservable					Weighted
Company	Input	Assets		Liabilities		Technique	Input (a)	Low		High		Average (b)
		(in millions)
AEP	Energy Contracts	$	207	$	137	Discounted Cash Flow	Forward Market Price	$	6.87	$	126.85	$	50.12
AEP	FTRs	69		7		Discounted Cash Flow	Forward Market Price	(32.49)		35.84		(0.24)
APCo	FTRs	22		1		Discounted Cash Flow	Forward Market Price	(0.39)		11.22		2.27
I&M	FTRs	3		1		Discounted Cash Flow	Forward Market Price	(0.75)		12.16		1.02
OPCo	Energy Contracts	—		32		Discounted Cash Flow	Forward Market Price	21.59		84.40		50.10
PSO	FTRs	21		—		Discounted Cash Flow	Forward Market Price	(32.49)		7.80		(7.34)
SWEPCo	FTRs	16		1		Discounted Cash Flow	Forward Market Price	(32.49)		7.80		(7.34)

December 31, 2025

							Significant	Input/Range
	Type of	Fair Value				Valuation	Unobservable					Weighted
Company	Input	Assets		Liabilities		Technique	Input (a)	Low		High		Average (b)
		(in millions)
AEP	Energy Contracts	$	224	$	144	Discounted Cash Flow	Forward Market Price	$	5.65	$	141.75	$	50.61
AEP	FTRs	187		8		Discounted Cash Flow	Forward Market Price	(32.49)		21.68		0.49
APCo	FTRs	81		—		Discounted Cash Flow	Forward Market Price	(0.26)		17.55		3.47
I&M	FTRs	9		—		Discounted Cash Flow	Forward Market Price	(0.46)		21.68		1.60
OPCo	Energy Contracts	—		33		Discounted Cash Flow	Forward Market Price	21.44		85.92		50.10
PSO	FTRs	43		2		Discounted Cash Flow	Forward Market Price	(32.49)		8.54		(5.49)
SWEPCo	FTRs	37		2		Discounted Cash Flow	Forward Market Price	(32.49)		8.54		(5.49)

(a)Represents market prices in dollars per MWh.

(b)The weighted average is the product of the forward market price of the underlying commodity and volume weighted by term.

Schedule of Sensitivity of Fair Value Measurements

The following table provides the measurement uncertainty of fair value measurements to increases (decreases) in significant unobservable inputs related to Energy Contracts and FTRs for the Registrants as of March 31, 2026 and December 31, 2025:

Significant Unobservable Input	Position	Change in Input	Impact on Fair Value Measurement
Forward Market Price	Buy	Increase (Decrease)	Higher (Lower)
Forward Market Price	Sell	Increase (Decrease)	Lower (Higher)