v3.26.3
Postretirement Benefit Obligations
 9 Months Ended
Sep. 30, 2026
Postemployment Benefits [Abstract]  
Postretirement Benefit Obligations
12. Postretirement Benefit Obligations
TES and certain subsidiaries sponsor postemployment benefits which include defined benefit pension plans, health and welfare postretirement plans (other postretirement benefit plans), and a defined contribution plan.
The components of net periodic benefit costs for the periods were:
 Three Months Ended September 30,Nine Months Ended September 30,
2026202520262025
Postretirement benefits service cost (a)
$1 $1 $2 $2 
Postretirement benefit (gain) loss
Interest cost$16 $17 $49 $51 
Expected return on plan assets(19)(19)(56)(56)
Amortization of:
Postretirement prior service cost (credit)(1)(1)(3)(3)
Postretirement benefit (gain) loss, net (b)
$(4)$(3)$(10)$(8)
Net periodic defined benefit cost (credit)$(3)$(2)$(8)$(6)
__________________
(a)Activity presented as “Operation, maintenance and development” on the Consolidated Statements of Operations.
(b)Activity presented as “Other non-operating income (expense), net” on the Consolidated Statements of Operations.
Talen Montana Pension Plan
On October 1, 2026, the Company notified the participants of the Talen Montana defined benefit plan of its intent to terminate the plan effective December 1, 2026.