v3.26.3
BENEFIT PLANS (Tables)
 9 Months Ended
Sep. 30, 2026
Retirement Benefits [Abstract]  
Schedule of Components of Net Periodic Benefit Cost
Pension Plans

Three Months Ended September 30, 2026AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$24 $2 $2 $5 $2 $2 $2 
Interest Cost51 5 6 6 5 3 3 
Expected Return on Plan Assets(63)(5)(9)(10)(8)(4)(4)
Amortization of Net Actuarial Loss11 — 2 1 1 1 1 
Settlements (a)(1)(5)— — 1 1 — 
Net Periodic Benefit Cost (Credit)$22 $(3)$1 $2 $1 $3 $2 

Three Months Ended September 30, 2025AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$24 $3 $2 $4 $2 $2 $2 
Interest Cost53 4 6 6 5 3 3 
Expected Return on Plan Assets(70)(6)(9)(10)(7)(4)(4)
Amortization of Net Actuarial Loss4 — 1 — — — 1 
Net Periodic Benefit Cost$11 $1 $— $— $— $1 $2 

Nine Months Ended September 30, 2026AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$75 $7 $7 $10 $7 $5 $7 
Interest Cost154 13 18 18 14 8 9 
Expected Return on Plan Assets(191)(15)(25)(26)(20)(11)(11)
Amortization of Net Actuarial Loss32 2 4 3 3 2 2 
Settlements (a)(8)(13)— — (5)5 — 
Net Periodic Benefit Cost (Credit)$62 $(6)$4 $5 $(1)$9 $7 

Nine Months Ended September 30, 2025AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$72 $7 $6 $9 $7 $5 $6 
Interest Cost159 13 19 19 14 8 9 
Expected Return on Plan Assets(211)(17)(28)(29)(22)(12)(11)
Amortization of Net Actuarial Loss12 1 2 1 1 1 1 
Net Periodic Benefit Cost (Credit)$32 $4 $(1)$— $— $2 $5 

(a)Represents deferrals of regulatory activity.
OPEB

Three Months Ended September 30, 2026AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$1 $— $— $— $— $— $— 
Interest Cost8 1 1 1 2 — 1 
Expected Return on Plan Assets(29)(2)(4)(4)(4)(2)(2)
Amortization of Prior Service Credit(1)— — — — — — 
Amortization of Net Actuarial Gain(1)— — — — — — 
Net Periodic Benefit Credit$(22)$(1)$(3)$(3)$(2)$(2)$(1)

Three Months Ended September 30, 2025AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$1 $— $— $— $— $— $— 
Interest Cost9 1 1 1 1 1 1 
Expected Return on Plan Assets(29)(2)(4)(3)(3)(2)(2)
Amortization of Prior Service Credit(1)— — — — — — 
Net Periodic Benefit Credit$(20)$(1)$(3)$(2)$(2)$(1)$(1)

Nine Months Ended September 30, 2026AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$3 $— $— $— $— $— $— 
Interest Cost23 2 3 3 2 1 2 
Expected Return on Plan Assets(88)(7)(12)(11)(9)(5)(6)
Amortization of Prior Service Credit(2)— — — — — — 
Amortization of Net Actuarial Gain(2)— — — — — — 
Net Periodic Benefit Credit$(66)$(5)$(9)$(8)$(7)$(4)$(4)

Nine Months Ended September 30, 2025AEPAEP TexasAPCoI&MOPCoPSOSWEPCo
(in millions)
Service Cost$3 $— $— $— $— $— $— 
Interest Cost26 2 4 3 3 1 2 
Expected Return on Plan Assets(85)(7)(13)(10)(9)(4)(6)
Amortization of Prior Service Credit(2)— — — — — — 
Amortization of Net Actuarial Gain(1)— — — — — — 
Net Periodic Benefit Credit$(59)$(5)$(9)$(7)$(6)$(3)$(4)
Schedule of Qualified Pension Contribution The following table provides details of the contribution by Registrant:
CompanyQualified Pension Plan
(in millions)
AEP$95 
AEP Texas12 
APCo— 
I&M2 
PSO1 
SWEPCo9