RETIREMENT BENEFITS (Tables)

12 Months Ended

Dec. 31, 2019

Retirement Benefits [Abstract]

Schedule of defined benefit plan

In December 2019, the Registrants voluntarily contributed the following amounts to the qualified pension plan:

	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
Contributions to qualified pension plan	$	1,136	$	362	$	200	$	54	$	24	$	145

The portion of the Southern Company system's pension and other postretirement benefit plans attributable to Gulf Power reflected in Southern Company's consolidated balance sheet as held for sale at December 31, 2018 consisted of:

	Pension Plans			Other Postretirement Benefit Plans
	(in millions)
Projected benefit obligation	$	526		$	69
Plan assets	492			17
Accrued liability	$	(34	)	$	(52	)

Summary of actuarial assumptions

The weighted average rates assumed in the actuarial calculations used to determine both the net periodic costs for the pension and other postretirement benefit plans for the following year and the benefit obligations as of the measurement date are presented below.

	2019
Assumptions used to determine net periodic costs:	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
Pension plans
Discount rate – benefit obligations	4.49	%	4.51	%	4.48	%	4.49	%	4.65	%	4.47	%
Discount rate – interest costs	4.12		4.14		4.10		4.12		4.35		4.11
Discount rate – service costs	4.70		4.73		4.72		4.73		4.75		4.57
Expected long-term return on plan assets	7.75		7.75		7.75		7.75		7.75		7.75
Annual salary increase	4.34		4.46		4.46		4.46		4.46		3.07
Other postretirement benefit plans
Discount rate – benefit obligations	4.37	%	4.40	%	4.36	%	4.35	%	4.50	%	4.32	%
Discount rate – interest costs	3.98		4.01		3.97		3.95		4.14		3.91
Discount rate – service costs	4.63		4.67		4.64		4.64		4.65		4.56
Expected long-term return on plan assets	6.86		6.76		6.85		6.79		—		6.49
Annual salary increase	4.34		4.46		4.46		4.46		4.46		3.07

	2018
Assumptions used to determine net periodic costs:	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
Pension plans
Discount rate – benefit obligations	3.80	%	3.81	%	3.79	%	3.80	%	3.94	%	3.74	%
Discount rate – interest costs	3.45		3.45		3.42		3.46		3.69		3.41
Discount rate – service costs	3.98		4.00		3.99		3.99		4.01		3.84
Expected long-term return on plan assets	7.95		7.95		7.95		7.95		7.95		7.95
Annual salary increase	4.34		4.46		4.46		4.46		4.46		3.07
Other postretirement benefit plans
Discount rate – benefit obligations	3.68	%	3.71	%	3.68	%	3.68	%	3.81	%	3.62	%
Discount rate – interest costs	3.29		3.31		3.29		3.29		3.47		3.21
Discount rate – service costs	3.91		3.93		3.91		3.91		3.93		3.82
Expected long-term return on plan assets	6.83		6.83		6.80		6.99		—		5.89
Annual salary increase	4.34		4.46		4.46		4.46		4.46		3.07

	2017
Assumptions used to determine net periodic costs:	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Company Gas
Pension plans
Discount rate – benefit obligations	4.40	%	4.44	%	4.40	%	4.44	%	4.39	%
Discount rate – interest costs	3.77		3.76		3.72		3.81		3.76
Discount rate – service costs	4.81		4.85		4.83		4.83		4.64
Expected long-term return on plan assets	7.92		7.95		7.95		7.95		7.60
Annual salary increase	4.37		4.46		4.46		4.46		3.50
Other postretirement benefit plans
Discount rate – benefit obligations	4.23	%	4.27	%	4.23	%	4.22	%	4.15	%
Discount rate – interest costs	3.54		3.58		3.55		3.55		3.40
Discount rate – service costs	4.64		4.70		4.63		4.65		4.55
Expected long-term return on plan assets	6.84		6.83		6.79		6.88		6.03
Annual salary increase	4.37		4.46		4.46		4.46		3.50

	2019
Assumptions used to determine benefit obligations:	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
Pension plans
Discount rate	3.41	%	3.44	%	3.40	%	3.41	%	3.52	%	3.39	%
Annual salary increase	4.73		4.73		4.73		4.73		4.73		4.73
Other postretirement benefit plans
Discount rate	3.24	%	3.28	%	3.22	%	3.22	%	3.39	%	3.19	%
Annual salary increase	4.73		4.73		4.73		4.73		4.73		4.73

	2018
Assumptions used to determine benefit obligations:	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
Pension plans
Discount rate	4.49	%	4.51	%	4.48	%	4.49	%	4.65	%	4.47	%
Annual salary increase	4.34		4.46		4.46		4.46		4.46		3.07
Other postretirement benefit plans
Discount rate	4.37	%	4.40	%	4.36	%	4.35	%	4.50	%	4.32	%
Annual salary increase	4.34		4.46		4.46		4.46		4.46		3.07

Schedule of health care cost trend rates

The weighted average medical care cost trend rates used in measuring the APBO for the Registrants at December 31, 2019 were as follows:

	Initial Cost Trend Rate		Ultimate Cost Trend Rate		Year That Ultimate Rate is Reached
Pre-65	6.00	%	4.50	%	2027
Post-65 medical	5.00		4.50		2027
Post-65 prescription	6.50		4.50		2027

Schedule of accumulated and projected benefit obligations

The total accumulated benefit obligation for the pension plans at December 31, 2019 and 2018 was as follows:

	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
December 31, 2019	$	13,391	$	3,053	$	4,222	$	615	$	151	$	963
December 31, 2018	11,683		2,550		3,613		513		101		842

The projected benefit obligations for the qualified and non-qualified pension plans at December 31, 2019 are shown in the following table. All pension plan assets are related to the qualified pension plan.

	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
Projected benefit obligations:
Qualified pension plan	$	14,055	$	3,286	$	4,480	$	639	$	159	$	999
Non-qualified pension plan	733		118		130		31		26		68

Changes in projected benefit obligations and fair value of plan assets

Changes in the projected benefit obligations and the fair value of plan assets during the plan years ended December 31, 2019 and 2018 were as follows:

	2019
	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
Change in benefit obligation
Benefit obligation at beginning of year	$	12,763		$	2,816		$	3,905		$	557		$	123		$	907
Dispositions	(509		)	—			—			—			—			—
Service cost	292			69			74			12			7			25
Interest cost	492			114			156			22			5			36
Benefits paid	(596		)	(125		)	(194		)	(26		)	(4		)	(64		)
Actuarial (gain) loss	2,346			530			669			106			54			163
Balance at end of year	14,788			3,404			4,610			671			185			1,067
Change in plan assets
Fair value of plan assets at beginning of year	11,611			2,575			3,663			505			123			798
Dispositions	(509		)	—			—			—			—			—
Actual return (loss) on plan assets	2,343			524			730			103			43			172
Employer contributions	1,208			383			243			59			7			144
Benefits paid	(596		)	(125		)	(194		)	(26		)	(4		)	(64		)
Fair value of plan assets at end of year	14,057			3,357			4,442			641			169			1,050
Accrued liability	$	(731	)	$	(47	)	$	(168	)	$	(30	)	$	(16	)	$	(17	)

	2018
	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
Change in benefit obligation
Benefit obligation at beginning of year	$	13,808		$	2,998		$	4,188		$	602		$	139		$	1,184
Dispositions	(107		)	—			—			—			(3		)	(104		)
Service cost	359			78			87			17			9			34
Interest cost	464			101			139			20			5			39
Benefits paid	(618		)	(124		)	(191		)	(24		)	(3		)	(98		)
Actuarial (gain) loss	(1,143		)	(237		)	(318		)	(58		)	(24		)	(148		)
Balance at end of year	12,763			2,816			3,905			557			123			907
Change in plan assets
Fair value of plan assets at beginning of year	12,992			2,836			4,058			563			138			1,068
Dispositions	(107		)	—			—			—			(3		)	(104		)
Actual return (loss) on plan assets	(711		)	(150		)	(218		)	(37		)	(9		)	(70		)
Employer contributions	55			13			14			3			—			2
Benefits paid	(618		)	(124		)	(191		)	(24		)	(3		)	(98		)
Fair value of plan assets at end of year	11,611			2,575			3,663			505			123			798
Accrued liability	$	(1,152	)	$	(241	)	$	(242	)	$	(52	)	$	—		$	(109	)

Amounts recognized in balance sheets

Amounts recognized in the balance sheets at December 31, 2019 and 2018 related to the Registrants' pension plans consist of the following:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
December 31, 2019:
Prepaid pension costs	$	2		$	71		$	—		$	2		$	10		$	—
Other regulatory assets, deferred(*)	4,072			1,130			1,416			204			—			172
Other deferred charges and assets	—			—			—			—			—			82
Other current liabilities	(54		)	(8		)	(11		)	(2		)	(2		)	(2		)
Employee benefit obligations	(679		)	(110		)	(157		)	(30		)	(24		)	(97		)
Other regulatory liabilities, deferred	(79		)	—			—			—			—			—
AOCI	185			—			—			—			46			(14		)
December 31, 2018:
Prepaid pension costs	$	—		$	—		$	—		$	—		$	1		$	—
Other regulatory assets, deferred(*)	3,566			955			1,230			167			—			160
Other deferred charges and assets	—			—			—			—			—			74
Other current liabilities	(55		)	(12		)	(15		)	(3		)	—			(3		)
Employee benefit obligations	(1,097		)	(229		)	(227		)	(49		)	(1		)	(179		)
Other regulatory liabilities, deferred	(108		)	—			—			—			—			—
AOCI	97			—			—			—			26			(44		)

(*)

Amounts for Southern Company exclude regulatory assets of $252 million and $268 million at December 31, 2019 and 2018, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its 2016 acquisition by Southern Company.

Presented below are the amounts included in regulatory assets at December 31, 2019 and 2018 related to the portion of the defined benefit pension plan attributable to Southern Company, the traditional electric operating companies, and Southern Company Gas that had not yet been recognized in net periodic pension cost.

	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Company Gas
	(in millions)
Balance at December 31, 2019
Regulatory assets:
Prior service cost	$	13	$	6	$	10	$	2	$	(15	)
Net (gain) loss	3,980		1,124		1,406		201		113
Regulatory amortization	—		—		—		—		74
Total regulatory assets(*)	$	3,993	$	1,130	$	1,416	$	203	$	172
Balance at December 31, 2018
Regulatory assets:
Prior service cost	$	17	$	6	$	12	$	2	$	(17	)
Net (gain) loss	3,441		949		1,218		165		83
Regulatory amortization	—		—		—		—		94
Total regulatory assets(*)	$	3,458	$	955	$	1,230	$	167	$	160

(*)

Amounts for Southern Company exclude regulatory assets of $252 million and $268 million at December 31, 2019 and 2018, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its 2016 acquisition by Southern Company.

Amounts recognized in the balance sheets at December 31, 2019 and 2018 related to the Registrants' other postretirement benefit plans consist of the following:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
December 31, 2019:
Other regulatory assets, deferred(a)	$	183		$	3		$	96		$	10		$	—		$	(11	)
Other current liabilities	(5		)	—			—			—			—			—
Employee benefit obligations(b)	(919		)	(49		)	(339		)	(61		)	(11		)	(135		)
Other regulatory liabilities, deferred	(62		)	(2		)	—			—			—			—
AOCI	2			—			—			—			2			(4		)
December 31, 2018:
Other regulatory assets, deferred(a)	$	99		$	—		$	60		$	6		$	—		$	(4	)
Other current liabilities	(6		)	—			—			—			—			—
Employee benefit obligations(b)	(931		)	(43		)	(331		)	(58		)	(9		)	146
Other regulatory liabilities, deferred	(77		)	(8		)	—			(2		)	—			—
AOCI	(4		)	—			—			—			1			(4		)

(a) Amounts for Southern Company exclude regulatory assets of $50 million and $57 million at December 31, 2019 and 2018, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its 2016 acquisition by Southern Company.

(b) Included in other deferred credits and liabilities on Southern Power's consolidated balance sheets.

Presented below are the amounts included in net regulatory assets (liabilities) at December 31, 2019 and 2018 related to the other postretirement benefit plans of Southern Company, the traditional electric operating companies, and Southern Company Gas that had not yet been recognized in net periodic other postretirement benefit cost.

	Southern Company		Alabama Power			Georgia Power		Mississippi Power		Southern Company Gas
	(in millions)
Balance at December 31, 2019:
Regulatory assets (liabilities):
Prior service cost	$	11	$	3		$	4	$	—	$	1
Net (gain) loss	110		(2		)	92		10		(43		)
Regulatory amortization	—		—			—		—		31
Total regulatory assets (liabilities)(*)	$	121	$	1		$	96	$	10	$	(11	)
Balance at December 31, 2018:
Regulatory assets (liabilities):
Prior service cost	$	14	$	8		$	4	$	—	$	2
Net (gain) loss	8		(16		)	56		4		(43		)
Regulatory amortization	—		—			—		—		37
Total regulatory assets (liabilities)(*)	$	22	$	(8	)	$	60	$	4	$	(4	)

(*)

Amounts for Southern Company exclude regulatory assets of $50 million and $57 million at December 31, 2019 and 2018, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its 2016 acquisition by Southern Company.

Changes in balances of regulatory assets and regulatory liabilities related to defined benefit pension plans

The changes in the balance of regulatory assets related to the portion of the defined benefit pension plan attributable to Southern Company, the traditional electric operating companies, and Southern Company Gas for the years ended December 31, 2019 and 2018 are presented in the following table:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Company Gas
	(in millions)
Regulatory assets (liabilities):(*)
Balance at December 31, 2017	$	3,155		$	890		$	1,105		$	158		$	217
Net (gain) loss	498			120			196			19			20
Change in prior service costs	1			—			—			—			(18		)
Dispositions	12			—			—			—			(34		)
Reclassification adjustments:
Amortization of prior service costs	(4		)	(1		)	(2		)	—			2
Amortization of net gain (loss)	(204		)	(54		)	(69		)	(10		)	(12		)
Amortization of regulatory assets(*)	—			—			—			—			(15		)
Total reclassification adjustments	(208		)	(55		)	(71		)	(10		)	(25		)
Total change	303			65			125			9			(57		)
Balance at December 31, 2018	$	3,458		$	955		$	1,230		$	167		$	160
Net (gain) loss	801			213			231			42			30
Dispositions	(144		)	—			—			—			—
Reclassification adjustments:
Amortization of prior service costs	(3		)	(1		)	(1		)	—			2
Amortization of net gain (loss)	(119		)	(37		)	(44		)	(6		)	—
Amortization of regulatory assets(*)	—			—			—			—			(20		)
Total reclassification adjustments	(122		)	(38		)	(45		)	(6		)	(18		)
Total change	535			175			186			36			12
Balance at December 31, 2019	$	3,993		$	1,130		$	1,416		$	203		$	172

(*)

Amounts for Southern Company exclude regulatory assets of $252 million and $268 million at December 31, 2019 and 2018, respectively, associated with unamortized amounts in Southern Company Gas' pension plans prior to its 2016 acquisition by Southern Company.

The changes in the balance of net regulatory assets (liabilities) related to the other postretirement benefit plans for the plan years ended December 31, 2019 and 2018 are presented in the following table:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Company Gas
	(in millions)
Net regulatory assets (liabilities):(*)
Balance at December 31, 2017	$	341		$	56		$	202		$	17		$	46
Net (gain) loss	(298		)	(60		)	(132		)	(12		)	(42		)
Change in prior service costs	—			—			—			—			(2		)
Reclassification adjustments:
Amortization of prior service costs	(7		)	(4		)	(1		)	—			—
Amortization of net gain (loss)	(14		)	(1		)	(9		)	(1		)	—
Amortization of regulatory assets(*)	—			—			—			—			(6		)
Total reclassification adjustments	(21		)	(5		)	(10		)	(1		)	(6		)
Total change	(319		)	(65		)	(142		)	(13		)	(50		)
Balance at December 31, 2018	$	22		$	(9	)	$	60		$	4		$	(4	)
Net (gain) loss	90			14			37			6			(1		)
Dispositions	5			—			—			—			—
Change in prior service costs	5			—			—			—			—
Reclassification adjustments:
Amortization of prior service costs	(3		)	(4		)	—			—			—
Amortization of net gain (loss)	2			—			(1		)	—			—
Amortization of regulatory assets(*)	—			—			—			—			(6		)
Total reclassification adjustments	(1		)	(4		)	(1		)	—			(6		)
Total change	99			10			36			6			(7		)
Balance at December 31, 2019	$	121		$	1		$	96		$	10		$	(11	)

(*)

Amounts for Southern Company exclude regulatory assets of $50 million and $57 million at December 31, 2019 and 2018, respectively, associated with unamortized amounts in Southern Company Gas' other postretirement benefit plans prior to its 2016 acquisition by Southern Company.

Amounts included in AOCI related to defined benefit pension plans

Presented below are the amounts included in AOCI at December 31, 2019 and 2018 related to the portion of the defined benefit pension plan attributable to Southern Company, Southern Power, and Southern Company Gas that had not yet been recognized in net periodic pension cost.

	Southern Company			Southern Power		Southern Company Gas
	(in millions)
Balance at December 31, 2019
AOCI:
Prior service cost	$	(3	)	$	—	$	(6	)
Net (gain) loss	188			46		(8		)
Total AOCI	$	185		$	46	$	(14	)
Balance at December 31, 2018
AOCI:
Prior service cost	$	(3	)	$	—	$	(6	)
Net (gain) loss	100			26		(38		)
Total AOCI	$	97		$	26	$	(44	)

Presented below are the amounts included in AOCI at December 31, 2019 and 2018 related to the other postretirement benefit plans of Southern Company, Southern Power, and Southern Company Gas that had not yet been recognized in net periodic other postretirement benefit cost.

	Southern Company			Southern Power		Southern Company Gas
	(in millions)
Balance at December 31, 2019
AOCI:
Prior service cost	$	1		$	—	$	1
Net (gain) loss	1			2		(5		)
Total AOCI	$	2		$	2	$	(4	)
Balance at December 31, 2018
AOCI:
Prior service cost	$	1		$	—	$	1
Net (gain) loss	(5		)	1		(5		)
Total AOCI	$	(4	)	$	1	$	(4	)

Components of OCI related to defined benefit pension plan

The components of OCI related to the portion of the defined benefit pension plan attributable to Southern Company, Southern Power, and Southern Company Gas for the years ended December 31, 2019 and 2018 are presented in the following table:

	Southern Company			Southern Power			Southern Company Gas
	(in millions)
AOCI:
Balance at December 31, 2017	$	107		$	33		$	(42	)
Net (gain) loss	7			(5		)	6
Dispositions	(8		)	—			(8		)
Reclassification adjustments:
Amortization of net gain (loss)	(9		)	(2		)	—
Total reclassification adjustments	(9		)	(2		)	—
Total change	(10		)	(7		)	(2		)
Balance at December 31, 2018	$	97		$	26		$	(44	)
Net (gain) loss	88			20			30
Balance at December 31, 2019	$	185		$	46		$	(14	)

The components of OCI related to the other postretirement benefit plans for the plan years ended December 31, 2019 and 2018 are presented in the following table:

	Southern Company			Southern Power			Southern Company Gas
	(in millions)
AOCI:
Balance at December 31, 2017	$	4		$	3		$	(3	)
Net (gain) loss	(8		)	(2		)	(2		)
Change from employee transfer	—			—			1
Total change	(8		)	(2		)	(1		)
Balance at December 31, 2018	$	(4	)	$	1		$	(4	)
Net (gain) loss	5			1			—
Reclassification adjustments:
Amortization of net gain (loss)	1			—			—
Total change	6			1			—
Balance at December 31, 2019	$	2		$	2		$	(4	)

Components of net periodic benefit cost

Components of net periodic pension cost for the Registrants were as follows:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
2019
Service cost	$	292		$	69		$	74		$	12		$	7		$	25
Interest cost	492			114			156			22			5			36
Expected return on plan assets	(885		)	(206		)	(292		)	(40		)	(10		)	(60		)
Recognized net (gain) loss	120			37			44			6			1			2
Net amortization	2			—			1			—			—			14
Prior service cost	—			—			—			—			—			(3		)
Net periodic pension cost	$	21		$	14		$	(17	)	$	—		$	3		$	14
2018
Service cost	$	359		$	78		$	87		$	17		$	9		$	34
Interest cost	464			101			139			20			5			39
Expected return on plan assets	(943		)	(207		)	(296		)	(41		)	(10		)	(75		)
Recognized net (gain) loss	213			54			69			10			1			12
Net amortization	4			1			2			—			—			15
Prior service cost	—			—			—			—			—			(2		)
Net periodic pension cost	$	97		$	27		$	1		$	6		$	5		$	23
2017
Service cost	$	293		$	63		$	74		$	15					$	23
Interest cost	455			98			138			20						42
Expected return on plan assets	(897		)	(196		)	(283		)	(40		)				(70		)
Recognized net (gain) loss	162			42			57			7						18
Net amortization	12			2			3			1						1
Net periodic pension cost	$	25		$	9		$	(11	)	$	3					$	14

Components of the other postretirement benefit plans' net periodic cost for the Registrants were as follows:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power		Southern Company Gas
	(in millions)
2019
Service cost	$	18		$	5		$	5		$	1		$	1	$	1
Interest cost	69			16			26			3			—		9
Expected return on plan assets	(65		)	(26		)	(25		)	(2		)	—		(7		)
Net amortization	—			4			1			—			—		6
Net periodic postretirement benefit cost	$	22		$	(1	)	$	7		$	2		$	1	$	9
2018
Service cost	$	24		$	6		$	6		$	1		$	1	$	2
Interest cost	75			17			28			3			—		10
Expected return on plan assets	(69		)	(26		)	(25		)	(2		)	—		(7		)
Net amortization	21			5			10			1			—		6
Net periodic postretirement benefit cost	$	51		$	2		$	19		$	3		$	1	$	11
2017
Service cost	$	24		$	6		$	7		$	1				$	2
Interest cost	79			17			29			3					10
Expected return on plan assets	(66		)	(25		)	(25		)	(1		)			(7		)
Net amortization	20			5			9			1					1
Net periodic postretirement benefit cost	$	57		$	3		$	20		$	4				$	6

Estimated pension benefit payments

At December 31, 2019, estimated benefit payments were as follows:

	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
Benefit Payments:
2020	$	628	$	135	$	204	$	27	$	5	$	62
2021	646		141		208		28		6		62
2022	671		147		214		30		6		64
2023	693		153		220		30		6		62
2024	715		157		226		32		7		62
2025 to 2029	3,868		860		1,209		174		36		316

The Registrants' estimated benefit payments are reduced by drug subsidy receipts expected as a result of the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 as follows:

	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power		Southern Company Gas
	(in millions)
Benefit payments:
2020	$	130		$	29		$	49		$	6		$	—	$	18
2021	129			29			49			6			—		18
2022	129			29			49			6			1		18
2023	130			29			49			6			1		19
2024	129			29			48			6			1		18
2025 to 2029	630			145			238			29			3		83
Subsidy receipts:
2020	$	(5	)	$	(1	)	$	(2	)	$	—		$	—	$	—
2021	(6		)	(2		)	(2		)	—			—		—
2022	(6		)	(2		)	(3		)	—			—		—
2023	(6		)	(2		)	(3		)	—			—		—
2024	(6		)	(2		)	(3		)	(1		)	—		—
2025 to 2029	(30		)	(9		)	(13		)	(2		)	—		—
Total:
2020	$	125		$	28		$	47		$	6		$	—	$	18
2021	123			27			47			6			—		18
2022	123			27			46			6			1		18
2023	124			27			46			6			1		19
2024	123			27			45			5			1		18
2025 to 2029	600			136			225			27			3		83

Changes in the APBO and the fair value of plan assets

Changes in the APBO and the fair value of the Registrants' plan assets during the plan years ended December 31, 2019 and 2018 were as follows:

	2019
	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
Change in benefit obligation
Benefit obligation at beginning of year	$	1,865		$	403		$	675		$	81		$	9		$	244
Dispositions	(69		)	—			—			—			—			—
Service cost	18			5			5			1			1			1
Interest cost	69			16			26			3			—			9
Benefits paid	(126		)	(27		)	(47		)	(6		)	(1		)	(17		)
Actuarial (gain) loss	223			63			80			8			2			13
Retiree drug subsidy	5			2			3			—			—			—
Balance at end of year	1,985			462			742			87			11			250
Change in plan assets
Fair value of plan assets at beginning of year	928			360			344			23			—			98
Dispositions	(18		)	—			—			—			—			—
Actual return (loss) on plan assets	189			76			68			4			—			21
Employer contributions	83			2			35			5			1			13
Benefits paid	(121		)	(25		)	(44		)	(6		)	(1		)	(17		)
Fair value of plan assets at end of year	1,061			413			403			26			—			115
Accrued liability	$	(924	)	$	(49	)	$	(339	)	$	(61	)	$	(11	)	$	(135	)

	2018
	Southern Company			Alabama Power			Georgia Power			Mississippi Power			Southern Power			Southern Company Gas
	(in millions)
Change in benefit obligation
Benefit obligation at beginning of year	$	2,339		$	517		$	863		$	97		$	11		$	310
Dispositions	(18		)	—			—			—			—			(18		)
Service cost	24			6			6			1			1			2
Interest cost	75			17			28			3			—			10
Benefits paid	(129		)	(28		)	(47		)	(5		)	(1		)	(17		)
Actuarial (gain) loss	(432		)	(111		)	(178		)	(15		)	(2		)	(43		)
Retiree drug subsidy	6			2			3			—			—			—
Balance at end of year	1,865			403			675			81			9			244
Change in plan assets
Fair value of plan assets at beginning of year	1,053			406			386			25			—			125
Dispositions	(18		)	—			—			—			—			(18		)
Actual return (loss) on plan assets	(57		)	(25		)	(20		)	(1		)	—			(5		)
Employer contributions	73			5			22			4			1			13
Benefits paid	(123		)	(26		)	(44		)	(5		)	(1		)	(17		)
Fair value of plan assets at end of year	928			360			344			23			—			98
Accrued liability	$	(937	)	$	(43	)	$	(331	)	$	(58	)	$	(9	)	$	(146	)

Summary of investment strategies and benefit plan asset fair values

A description of the major asset classes that the pension and other postretirement benefit plans are comprised of, along with the valuation methods used for fair value measurement, is provided below:

Description	Valuation Methodology
Domestic equity: A mix of large and small capitalization stocks with generally an equal distribution of value and growth attributes, managed both actively and through passive index approaches. International equity: A mix of large and small capitalization growth and value stocks with developed and emerging markets exposure, managed both actively and through fundamental indexing approaches.	Domestic and international equities such as common stocks, American depositary receipts, and real estate investment trusts that trade on public exchanges are classified as Level 1 investments and are valued at the closing price in the active market. Equity funds with unpublished prices (such as commingled/pooled funds) are valued as Level 2 when the underlying holdings are comprised of Level 1 or Level 2 equity securities.
Fixed income: A mix of domestic and international bonds.	Investments in fixed income securities are generally classified as Level 2 investments and are valued based on prices reported in the market place. Additionally, the value of fixed income securities takes into consideration certain items such as broker quotes, spreads, yield curves, interest rates, and discount rates that apply to the term of a specific instrument.
Trust-owned life insurance (TOLI): Investments of taxable trusts aimed at minimizing the impact of taxes on the portfolio.	Investments in TOLI policies are classified as Level 2 investments and are valued based on the underlying investments held in the policy's separate accounts. The underlying assets are equity and fixed income pooled funds that are comprised of Level 1 and Level 2 securities.
Special situations: Investments in opportunistic strategies with the objective of diversifying and enhancing returns and exploiting short-term inefficiencies, as well as investments in promising new strategies of a longer-term nature. Real estate: Investments in traditional private market, equity-oriented investments in real properties (indirectly through pooled funds or partnerships) and in publicly traded real estate securities. Private equity: Investments in private partnerships that invest in private or public securities typically through privately-negotiated and/or structured transactions, including leveraged buyouts, venture capital, and distressed debt.	Investments in real estate, private equity, and special situations are generally classified as Net Asset Value as a Practical Expedient, since the underlying assets typically do not have publicly available observable inputs. The fund manager values the assets using various inputs and techniques depending on the nature of the underlying investments. Techniques may include purchase multiples for comparable transactions, comparable public company trading multiples, discounted cash flow analysis, prevailing market capitalization rates, recent sales of comparable investments, and independent third-party appraisals. The fair value of partnerships is determined by aggregating the value of the underlying assets less liabilities.

Fair values of plan assets

These fair values exclude cash, receivables related to investment income and pending investment sales, and payables related to pending investment purchases.

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs		Net Asset Value as a Practical Expedient					Target Allocation		Actual Allocation
At December 31, 2019:	(Level 1)			(Level 2)		(NAV)		Total
	(in millions)
Southern Company
Assets:
Equity:											51	%	51	%
Domestic equity	$	2,220		$	898	$	—	$	3,118
International equity	2,360			1,286		—		3,646
Fixed income:											23		29
U.S. Treasury, government, and agency bonds	—			965		—		965
Mortgage- and asset-backed securities	—			9		—		9
Corporate bonds	—			1,315		—		1,315
Pooled funds	—			684		—		684
Cash equivalents and other	1,317			—		—		1,317
Real estate investments	539			—		1,418		1,957			14		12
Special situations	—			—		155		155			3		1
Private equity	—			—		953		953			9		7
Total	$	6,436		$	5,157	$	2,526	$	14,119		100	%	100	%
Liabilities:
Derivatives	(1		)	—		—		(1		)
Total	$	6,435		$	5,157	$	2,526	$	14,118		100	%	100	%
Alabama Power
Assets:
Equity:											51	%	51	%
Domestic equity	$	530		$	214	$	—	$	744
International equity	564			307		—		871
Fixed income:											23		29
U.S. Treasury, government, and agency bonds	—			230		—		230
Mortgage- and asset-backed securities	—			2		—		2
Corporate bonds	—			314		—		314
Pooled funds	—			163		—		163
Cash equivalents and other	315			—		—		315
Real estate investments	129			—		339		468			14		12
Special situations	—			—		37		37			3		1
Private equity	—			—		228		228			9		7
Total	$	1,538		$	1,230	$	604	$	3,372		100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2019:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Georgia Power
Assets:
Equity:									51	%	51	%
Domestic equity	$	701	$	284	$	—	$	985
International equity	746		407		—		1,153
Fixed income:									23		29
U.S. Treasury, government, and agency bonds	—		305		—		305
Mortgage- and asset-backed securities	—		3		—		3
Corporate bonds	—		415		—		415
Pooled funds	—		216		—		216
Cash equivalents and other	416		—		—		416
Real estate investments	170		—		448		618		14		12
Special situations	—		—		49		49		3		1
Private equity	—		—		301		301		9		7
Total	$	2,033	$	1,630	$	798	$	4,461	100	%	100	%
Mississippi Power
Assets:
Equity:									51	%	51	%
Domestic equity	$	101	$	41	$	—	$	142
International equity	108		59		—		167
Fixed income:									23		29
U.S. Treasury, government, and agency bonds	—		44		—		44
Corporate bonds	—		60		—		60
Pooled funds	—		31		—		31
Cash equivalents and other	60		—		—		60
Real estate investments	25		—		65		90		14		12
Special situations	—		—		7		7		3		1
Private equity	—		—		43		43		9		7
Total	$	294	$	235	$	115	$	644	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2019:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Southern Power
Assets:
Equity:									51	%	51	%
Domestic equity	$	27	$	11	$	—	$	38
International equity	28		16		—		44
Fixed income:									23		29
U.S. Treasury, government, and agency bonds	—		12		—		12
Corporate bonds	—		16		—		16
Pooled funds	—		8		—		8
Cash equivalents and other	16		—		—		16
Real estate investments	6		—		17		23		14		12
Special situations	—		—		2		2		3		1
Private equity	—		—		11		11		9		7
Total	$	77	$	63	$	30	$	170	100	%	100	%
Southern Company Gas
Assets:
Equity:									51	%	51	%
Domestic equity	$	166	$	67	$	—	$	233
International equity	176		96		—		272
Fixed income:									23		29
U.S. Treasury, government, and agency bonds	—		72		—		72
Mortgage- and asset-backed securities	—		1		—		1
Corporate bonds	—		98		—		98
Pooled funds	—		51		—		51
Cash equivalents and other	98		—		—		98
Real estate investments	40		—		106		146		14		12
Special situations	—		—		12		12		3		1
Private equity	—		—		71		71		9		7
Total	$	480	$	385	$	189	$	1,054	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2018:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Southern Company
Assets:
Equity:									51	%	53	%
Domestic equity	$	2,102	$	1,030	$	—	$	3,132
International equity	1,344		1,325		—		2,669
Fixed income:									23		24
U.S. Treasury, government, and agency bonds	—		930		—		930
Mortgage- and asset-backed securities	—		7		—		7
Corporate bonds	—		1,195		—		1,195
Pooled funds	—		654		—		654
Cash equivalents and other	270		2		—		272
Real estate investments	419		—		1,361		1,780		14		15
Special situations	—		—		171		171		3		1
Private equity	—		—		821		821		9		7
Total	$	4,135	$	5,143	$	2,353	$	11,631	100	%	100	%
Alabama Power
Assets:
Equity:									51	%	53	%
Domestic equity	$	466	$	228	$	—	$	694
International equity	298		293		—		591
Fixed income:									23		24
U.S. Treasury, government, and agency bonds	—		206		—		206
Mortgage- and asset-backed securities	—		2		—		2
Corporate bonds	—		265		—		265
Pooled funds	—		145		—		145
Cash equivalents and other	60		1		—		61
Real estate investments	93		—		302		395		14		15
Special situations	—		—		38		38		3		1
Private equity	—		—		182		182		9		7
Total	$	917	$	1,140	$	522	$	2,579	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2018:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Georgia Power
Assets:
Equity:									51	%	53	%
Domestic equity	$	663	$	325	$	—	$	988
International equity	424		418		—		842
Fixed income:									23		24
U.S. Treasury, government, and agency bonds	—		294		—		294
Mortgage- and asset-backed securities	—		2		—		2
Corporate bonds	—		377		—		377
Pooled funds	—		206		—		206
Cash equivalents and other	85		1		—		86
Real estate investments	132		—		429		561		14		15
Special situations	—		—		54		54		3		1
Private equity	—		—		259		259		9		7
Total	$	1,304	$	1,623	$	742	$	3,669	100	%	100	%
Mississippi Power
Assets:
Equity:									51	%	53	%
Domestic equity	$	91	$	45	$	—	$	136
International equity	59		59		—		118
Fixed income:									23		24
U.S. Treasury, government, and agency bonds	—		40		—		40
Corporate bonds	—		52		—		52
Pooled funds	—		28		—		28
Cash equivalents and other	12		—		—		12
Real estate investments	18		—		59		77		14		15
Special situations	—		—		7		7		3		1
Private equity	—		—		36		36		9		7
Total	$	180	$	224	$	102	$	506	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2018:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Southern Power
Assets:
Equity:									51	%	53	%
Domestic equity	$	22	$	11	$	—	$	33
International equity	14		14		—		28
Fixed income:									23		24
U.S. Treasury, government, and agency bonds	—		10		—		10
Corporate bonds	—		13		—		13
Pooled funds	—		7		—		7
Cash equivalents and other	3		—		—		3
Real estate investments	4		—		15		19		14		15
Special situations	—		—		2		2		3		1
Private equity	—		—		9		9		9		7
Total	$	43	$	55	$	26	$	124	100	%	100	%
Southern Company Gas
Assets:
Equity:									51	%	53	%
Domestic equity	$	145	$	71	$	—	$	216
International equity	92		91		—		183
Fixed income:									23		24
U.S. Treasury, government, and agency bonds	—		64		—		64
Corporate bonds	—		82		—		82
Pooled funds	—		45		—		45
Cash equivalents and other	19		—		—		19
Real estate investments	29		—		94		123		14		15
Special situations	—		—		12		12		3		1
Private equity	—		—		56		56		9		7
Total	$	285	$	353	$	162	$	800	100	%	100	%

The fair values of the applicable Registrants' other postretirement benefit plan assets at December 31, 2019 and 2018 are presented below. The Registrants did not have any investments classified as Level 3 at December 31, 2019 or 2018. These fair value measurements exclude cash, receivables related to investment income, pending investment sales, and payables related to pending investment purchases.

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient		Total		Target Allocation		Actual Allocation
At December 31, 2019:	(Level 1)		(Level 2)		(NAV)
	(in millions)
Southern Company
Assets:
Equity:									63	%	64	%
Domestic equity	$	95	$	81	$	—	$	176
International equity	69		80		—		149
Fixed income:									28		30
U.S. Treasury, government, and agency bonds	—		31		—		31
Corporate bonds	—		35		—		35
Pooled funds	—		82		—		82
Cash equivalents and other	42		—		—		42
Trust-owned life insurance	—		463		—		463
Real estate investments	15		—		38		53		5		4
Special situations	—		—		4		4		1		—
Private equity	—		—		25		25		3		2
Total	$	221	$	772	$	67	$	1,060	100	%	100	%
Alabama Power
Assets:
Equity:									68	%	67	%
Domestic equity	$	26	$	8	$	—	$	34
International equity	21		11		—		32
Fixed income:									24		27
U.S. Treasury, government, and agency bonds	—		10		—		10
Corporate bonds	—		11		—		11
Pooled funds	—		6		—		6
Cash equivalents and other	12		—		—		12
Trust-owned life insurance	—		281		—		281
Real estate investments	5		—		12		17		4		4
Special situations	—		—		1		1		1		—
Private equity	—		—		8		8		3		2
Total	$	64	$	327	$	21	$	412	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient		Total		Target Allocation		Actual Allocation
At December 31, 2019:	(Level 1)		(Level 2)		(NAV)
	(in millions)
Georgia Power
Assets:
Equity:									60	%	61	%
Domestic equity	$	48	$	7	$	—	$	55
International equity	25		36		—		61
Fixed income:									33		34
U.S. Treasury, government, and agency bonds	—		7		—		7
Corporate bonds	—		11		—		11
Pooled funds	—		45		—		45
Cash equivalents and other	16		—		—		16
Trust-owned life insurance	—		182		—		182
Real estate investments	5		—		11		16		4		3
Special situations	—		—		1		1		1		—
Private equity	—		—		8		8		2		2
Total	$	94	$	288	$	20	$	402	100	%	100	%
Mississippi Power
Assets:
Equity:									43	%	41	%
Domestic equity	$	3	$	1	$	—	$	4
International equity	4		2		—		6
Fixed income:									37		42
U.S. Treasury, government, and agency bonds	—		6		—		6
Corporate bonds	—		2		—		2
Pooled funds	—		1		—		1
Cash equivalents and other	2		—		—		2
Real estate investments	1		—		2		3		11		10
Special situations	—		—		—		—		2		1
Private equity	—		—		1		1		7		6
Total	$	10	$	12	$	3	$	25	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient		Total		Target Allocation		Actual Allocation
At December 31, 2019:	(Level 1)		(Level 2)		(NAV)
	(in millions)
Southern Company Gas
Assets:
Equity:									72	%	73	%
Domestic equity	$	2	$	58	$	—	$	60
International equity	2		21		—		23
Fixed income:									26		25
U.S. Treasury, government, and agency bonds	—		1		—		1
Corporate bonds	—		1		—		1
Pooled funds	—		25		—		25
Cash equivalents and other	2		—		—		2
Real estate investments	—		—		1		1		1		1
Private equity	—		—		1		1		1		1
Total	$	6	$	106	$	2	$	114	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2018:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Southern Company
Assets:
Equity:									62	%	62	%
Domestic equity	$	100	$	76	$	—	$	176
International equity	45		75		—		120
Fixed income:									29		30
U.S. Treasury, government, and agency bonds	—		34		—		34
Corporate bonds	—		35		—		35
Pooled funds	—		81		—		81
Cash equivalents and other	13		—		—		13
Trust-owned life insurance	—		386		—		386
Real estate investments	13		—		40		53		5		5
Special situations	—		—		4		4		1		—
Private equity	—		—		24		24		3		3
Total	$	171	$	687	$	68	$	926	100	%	100	%
Alabama Power
Assets:
Equity:									64	%	66	%
Domestic equity	$	35	$	10	$	—	$	45
International equity	12		12		—		24
Fixed income:									28		28
U.S. Treasury, government, and agency bonds	—		10		—		10
Corporate bonds	—		11		—		11
Pooled funds	—		6		—		6
Cash equivalents and other	3		—		—		3
Trust-owned life insurance	—		233		—		233
Real estate investments	4		—		13		17		4		4
Special situations	—		—		2		2		1		—
Private equity	—		—		8		8		3		2
Total	$	54	$	282	$	23	$	359	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2018:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Georgia Power
Assets:
Equity:									60	%	59	%
Domestic equity	$	41	$	9	$	—	$	50
International equity	17		32		—		49
Fixed income:									33		35
U.S. Treasury, government, and agency bonds	—		7		—		7
Corporate bonds	—		10		—		10
Pooled funds	—		44		—		44
Cash equivalents and other	5		—		—		5
Trust-owned life insurance	—		153		—		153
Real estate investments	4		—		11		15		4		4
Special situations	—		—		2		2		1		—
Private equity	—		—		7		7		2		2
Total	$	67	$	255	$	20	$	342	100	%	100	%
Mississippi Power
Assets:
Equity:									41	%	42	%
Domestic equity	$	3	$	2	$	—	$	5
International equity	2		2		—		4
Fixed income:									38		39
U.S. Treasury, government, and agency bonds	—		6		—		6
Corporate bonds	—		2		—		2
Pooled funds	—		1		—		1
Cash equivalents and other	1		—		—		1
Real estate investments	1		—		2		3		11		12
Special situations	—		—		—		—		3		1
Private equity	—		—		1		1		7		6
Total	$	7	$	13	$	3	$	23	100	%	100	%

	Fair Value Measurements Using
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Net Asset Value as a Practical Expedient				Target Allocation		Actual Allocation
At December 31, 2018:	(Level 1)		(Level 2)		(NAV)		Total
	(in millions)
Southern Company Gas
Assets:
Equity:									71	%	69	%
Domestic equity	$	2	$	47	$	—	$	49
International equity	1		17		—		18
Fixed income:									25		28
U.S. Treasury, government, and agency bonds	—		1		—		1
Corporate bonds	—		1		—		1
Pooled funds	—		24		—		24
Cash equivalents and other	1		—		—		1
Real estate investments	—		—		1		1		2		2
Special situations	—		—		—		—		1		—
Private equity	—		—		1		1		1		1
Total	$	4	$	90	$	2	$	96	100	%	100	%

Total matching contributions

Total matching contributions made to the plans for 2019, 2018, and 2017 were as follows:

	Southern Company		Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
2019	$	113	$	25	$	27	$	4	$	2	$	15
2018	119		24		26		5		3		18
2017	118		23		26		5		N/A		19