Retirement Benefits (Tables)

9 Months Ended

Sep. 30, 2024

Components of the net periodic benefit costs for the three and nine months ended September 30, 2024 and 2023 are presented in the following tables.


	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
Three Months Ended September 30, 2024
Pension Plans
Service cost	$	73	$	17	$	18	$	3	$	2	$	7
Interest cost	159		37		47		7		2		11
Expected return on plan assets	(316)		(77)		(99)		(14)		(4)		(21)
Amortization:
Prior service costs	—		—		—		—		—		(1)
Regulatory asset	—		—		—		—		—		4
Net (gain) loss	14		4		6		—		(1)		—
Net periodic pension income	$	(70)	$	(19)	$	(28)	$	(4)	$	(1)	$	—

Postretirement Benefits
Service cost	$	4	$	1	$	1	$	—	$	—	$	—
Interest cost	16		4		6		1		—		2
Expected return on plan assets	(22)		(9)		(8)		(1)		—		(2)
Amortization:
Prior service costs	1		—		1		—		—		—
Regulatory asset	—		—		—		—		—		2
Net (gain) loss	(4)		—		(3)		1		—		(1)
Net periodic postretirement benefit cost (income)	$	(5)	$	(4)	$	(3)	$	1	$	—	$	1

Nine Months Ended September 30, 2024
Pension Plans
Service cost	$	219	$	51	$	53	$	9	$	5	$	21
Interest cost	476		111		143		21		6		32
Expected return on plan assets	(947)		(230)		(296)		(43)		(12)		(64)
Amortization:
Prior service costs	—		—		1		—		—		(2)
Regulatory asset	—		—		—		—		—		11
Net loss	41		12		15		2		—		—
Net periodic pension income	$	(211)	$	(56)	$	(84)	$	(11)	$	(1)	$	(2)

Postretirement Benefits
Service cost	$	11	$	3	$	3	$	—	$	—	$	1
Interest cost	49		12		17		2		—		6
Expected return on plan assets	(66)		(26)		(24)		(1)		—		(6)
Amortization:
Prior service costs	2		—		1		—		—		—
Regulatory asset	—		—		—		—		—		5
Net gain	(12)		(2)		(4)		—		—		(4)
Net periodic postretirement benefit cost (income)	$	(16)	$	(13)	$	(7)	$	1	$	—	$	2


	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
Three Months Ended September 30, 2023
Pension Plans
Service cost	$	69	$	16	$	17	$	2	$	2	$	6
Interest cost	156		37		48		7		2		11
Expected return on plan assets	(307)		(75)		(97)		(13)		(4)		(22)
Amortization:
Prior service costs	—		—		—		—		—		(1)
Regulatory asset	—		—		—		—		—		4
Net (gain) loss	8		2		4		1		—		(1)
Net periodic pension income	$	(74)	$	(20)	$	(28)	$	(3)	$	—	$	(3)

Postretirement Benefits
Service cost	$	4	$	1	$	1	$	—	$	—	$	—
Interest cost	18		5		6		1		—		2
Expected return on plan assets	(21)		(9)		(7)		(1)		—		(2)
Amortization:
Prior service costs	—		—		1		—		—		—
Regulatory asset	—		—		—		—		—		2
Net gain	(4)		(1)		(1)		—		—		(1)
Net periodic postretirement benefit cost (income)	$	(3)	$	(4)	$	—	$	—	$	—	$	1

Nine Months Ended September 30, 2023
Pension Plans
Service cost	$	207	$	48	$	51	$	8	$	5	$	18
Interest cost	469		109		143		21		6		32
Expected return on plan assets	(922)		(223)		(289)		(41)		(12)		(65)
Amortization:
Prior service costs	—		—		1		—		—		(2)
Regulatory asset	—		—		—		—		—		11
Net (gain) loss	24		7		10		1		—		(3)
Net periodic pension income	$	(222)	$	(59)	$	(84)	$	(11)	$	(1)	$	(9)

Postretirement Benefits
Service cost	$	11	$	3	$	3	$	—	$	—	$	1
Interest cost	53		13		19		2		—		6
Expected return on plan assets	(62)		(26)		(22)		(1)		—		(5)
Amortization:
Prior service costs	1		—		1		—		—		—
Regulatory asset	—		—		—		—		—		5
Net gain	(10)		(2)		(3)		—		—		(3)
Net periodic postretirement benefit cost (income)	$	(7)	$	(12)	$	(2)	$	1	$	—	$	4