v3.26.1
Postretirement Benefit Obligations
 6 Months Ended
Jun. 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 June 30,Six Months Ended June 30,
2026202520262025
Postretirement benefits service cost (a)
$— $— $1 $1 
Postretirement benefit (gain) loss
Interest cost$17 $17 $33 $34 
Expected return on plan assets(18)(18)(37)(37)
Amortization of:
Postretirement prior service cost (credit)(1)(1)(2)(2)
Postretirement benefit (gain) loss, net (b)
$(2)$(2)$(6)$(5)
Net periodic defined benefit cost (credit)$(2)$(2)$(5)$(4)
__________________
(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
The Talen Montana defined benefit pension plan was frozen as of April 30, 2026, and participants ceased accruing additional benefits.