REGULATORY MATTERS (Tables)

12 Months Ended

Dec. 31, 2019

Regulated Operations [Abstract]

Schedule of regulatory assets

Regulatory assets and (liabilities) reflected in the consolidated balance sheets of Southern Company at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans	$	4,423		$	3,658		(a,o)
Asset retirement obligations-asset	4,381			2,933			(b,o)
Remaining net book value of retired assets	1,275			211			(c)
Deferred income tax charges	803			799			(b,n)
Property damage reserves-asset	410			416			(d)
Environmental remediation-asset	349			366			(e,o)
Loss on reacquired debt	323			346			(f)
Under recovered regulatory clause revenues	254			407			(g)
Vacation pay	186			182			(h,o)
Long-term debt fair value adjustment	107			121			(i)
Other regulatory assets	492			581			(j)
Deferred income tax credits	(6,301		)	(6,455		)	(b,n)
Other cost of removal obligations	(2,084		)	(2,297		)	(b)
Customer refunds	(285		)	(293		)	(k)
Over recovered regulatory clause revenues	(205		)	(47		)	(g)
Property damage reserves-liability	(204		)	(76		)	(l)
Other regulatory liabilities	(86		)	(132		)	(m)
Total regulatory assets (liabilities), net	$	3,838		$	720

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) are approved by the respective PSC or regulatory agency and are as follows:

(a) Recovered and amortized over the average remaining service period, which may range up to 15 years. See Note 11 for additional information.

(b) AROs and other cost of removal obligations are recorded, deferred income tax assets are recovered, and deferred income tax liabilities are amortized over the related property lives, which may range up to 80 years. Asset retirement and removal liabilities will be settled and trued up following completion of the related activities. Included in the deferred income tax assets is $23 million for the retiree Medicare drug subsidy, which is being recovered and amortized through 2027.

(c) Amortized over periods not exceeding 18 years.

(d) Effective January 1, 2020, Georgia Power is recovering approximately $213 million annually for storm damage. See "Georgia Power – Rate Plans – 2019 ARP" and " – Storm Damage Recovery" herein for additional information.

(e) Recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 for additional information.

(f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2019, the remaining amortization periods do not exceed 34 years.

(g) Recorded and recovered or amortized over periods generally not exceeding six years.

(h) Recorded as earned by employees and recovered as paid, generally within one year.

(i) Recovered over the remaining life of the original debt issuances at acquisition, which range up to 19 years as of December 31, 2019.

(j) Comprised of numerous immaterial components including nuclear outage costs, fuel-hedging losses, cancelled construction projects, property tax, and other miscellaneous assets. These costs are amortized over remaining periods generally not exceeding eight years as of December 31, 2019.

(k) At December 31, 2019 and 2018, primarily includes approximately $53 million and $109 million, respectively, at Alabama Power and $110 million and $100 million, respectively, at Georgia Power as a result of each company exceeding its allowed retail return range, as well as approximately $105 million and $55 million, respectively, pursuant to the Georgia Power Tax Reform Settlement Agreement. See "Alabama Power – Rate RSE" and "Georgia Power – Rate Plans" herein for additional information.

(l) Amortized as related expenses are incurred. See "Alabama Power – Rate NDR" and "Mississippi Power – System Restoration Rider" herein for additional information.

(m) Comprised of numerous components including building leases, fuel-hedging gains, and other liabilities that are recovered over remaining periods not exceeding 20 years.

(n) As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization, including $778 million of liabilities being amortized over periods not exceeding six years as of December 31, 2019. See "Georgia Power," "Mississippi Power," and "Southern Company Gas" herein and Note 10 for additional information.

(o)

Not earning a return as offset in rate base by a corresponding asset or liability.

Regulatory assets and (liabilities) reflected in the balance sheets of Alabama Power at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans	$	1,131		$	947		(a,o)
Asset retirement obligations	1,043			147			(b)
Deferred income tax charges	245			241			(b,c,d)
(Over) under recovered regulatory clause revenues	(72		)	176			(e)
Regulatory clauses	142			142			(f)
Vacation pay	72			71			(g,o)
Loss on reacquired debt	52			56			(h)
Nuclear outage	78			49			(i)
Remaining net book value of retired assets	649			43			(j)
Other regulatory assets	67			57			(k,l)
Deferred income tax credits	(1,960		)	(2,027		)	(b,d)
Other cost of removal obligations	(412		)	(497		)	(b)
Customer refunds	(56		)	(142		)	(m)
Natural disaster reserve	(150		)	(20		)	(n)
Other regulatory liabilities	(19		)	(12		)	(l)
Total regulatory assets (liabilities), net	$	810		$	(769	)

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) have been accepted or approved by the Alabama PSC and are as follows:

(a) Recovered and amortized over the average remaining service period which may range up to 14 years. See Note 11 for additional information.

(b) Asset retirement and removal assets and liabilities are recorded, deferred income tax assets are recovered, and deferred income tax credits are amortized over the related property lives, which may range up to 53 years. Asset retirement and other cost of removal assets and liabilities will be settled and trued up following completion of the related activities.

(c) Included in the deferred income tax charges are $9 million for 2019 and $10 million for 2018 for the retiree Medicare drug subsidy, which is being recovered and amortized through 2027.

(d) As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization. The recovery and amortization of these amounts will occur ratably over the related property lives, which may range up to 53 years. See Note 10 for additional information.

(e) Recorded monthly and expected to be recovered or returned within three years. See "Rate CNP PPA," "Rate CNP Compliance," and" Rate ECR" herein for additional information.

(f) In accordance with an accounting order issued in 2017 by the Alabama PSC, these regulatory assets will be amortized concurrently with the effective date of Alabama Power's next depreciation study, which is expected to occur no later than 2022.

(g) Recorded as earned by employees and recovered as paid, generally within one year. This includes both vacation and banked holiday pay.

(h) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2019, the remaining amortization periods do not exceed 30 years.

(i) Nuclear outage costs are deferred to a regulatory asset when incurred and amortized over a subsequent 18-month period.

(j) Recorded and amortized over remaining periods not exceeding 18 years.

(k) Comprised of components including generation site selection/evaluation costs, which are capitalized upon initiation of related construction projects, if applicable, and PPA capacity costs, which are to be recovered over the next 12 months.

(l) Fuel-hedging assets and liabilities are recorded over the life of the underlying hedged purchase contracts, which generally do not exceed three and a half years. Upon final settlement, actual costs incurred are recovered through the energy cost recovery clause.

(m) Includes $53 million for 2019 and $109 million for 2018 due to the retail return exceeding the allowed range. The December 31, 2018 balance also includes a $33 million excess deferred tax liability used to increase the Rate NDR balance in 2019. See "Rate RSE," "Rate NDR," and "Tax Reform Accounting Order" herein for additional information.

(n) Amortized as expenses are incurred. See "Rate NDR" herein for additional information.

(o)

Not earning a return as offset in rate base by a corresponding asset or liability.

Regulatory assets and (liabilities) reflected in the balance sheets of Georgia Power at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans	$	1,516		$	1,295		(a, m)
Asset retirement obligations	3,119			2,644			(b, m)
Deferred income tax charges	523			522			(b, c, m)
Storm damage reserves	410			416			(d)
Remaining net book value of retired assets	596			127			(e)
Loss on reacquired debt	262			277			(f, m)
Vacation pay	93			91			(g, m)
Other cost of removal obligations	156			68			(b)
Environmental remediation	52			55			(h)
Fuel-hedging (realized and unrealized) losses	53			15			(i, m)
Other regulatory assets	50			120			(j)
Deferred income tax credits	(3,078		)	(3,080		)	(b, c)
Customer refunds	(229		)	(165		)	(k)
Other regulatory liabilities	(16		)	(7		)	(l, m)
Total regulatory assets (liabilities), net	$	3,507		$	2,378

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) are approved by the Georgia PSC and are as follows:

(a) Recovered and amortized over the average remaining service period which may range up to 13 years. See Note 11 for additional information.

(b) Effective January 1, 2020, Georgia Power is recovering CCR AROs through its Environmental Compliance Cost Recovery (ECCR) tariff and approximately $5 million annually for other AROs through its traditional base tariffs. See "Rate Plans – 2019 ARP" and "Integrated Resource Plan" herein for additional information on recovery of compliance costs for CCR AROs. Other cost of removal obligations, non-CCR AROs, and deferred income tax assets are recovered and deferred income tax liabilities are amortized over the related property lives, which may range up to 60 years. Included in the deferred income tax assets is $13 million for the retiree Medicare drug subsidy, which is being recovered and amortized through 2022. See Note 6 for additional information on AROs.

(c) As a result of the Tax Reform Legislation, these balances include $145 million of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 and approximately $660 million of deferred income tax liabilities, neither of which are subject to normalization. The recovery of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 is expected to be determined in a future regulatory proceeding. Effective January 1, 2020, the deferred income tax liabilities are being amortized through 2022. See "Rate Plans" herein and Note 10 for additional information.

(d) Effective January 1, 2020, Georgia Power is recovering $213 million annually for storm damage. See "Rate Plans – 2019 ARP" and "Storm Damage Recovery" herein and Note 1 under "Storm Damage Reserves" for additional information.

(e) The net book values of Plant Hammond Units 1 through 4 ($488 million at December 31, 2019) and Plant Branch Units 1 through 4 ($69 million and $87 million at December 31, 2019 and 2018, respectively) are being amortized over the units' remaining useful lives, which vary between 2020 and 2035. The net book values of Plant McIntosh Unit 1 ($30 million at December 31, 2019) and Plant Mitchell Unit 3 ($8 million and $9 million at December 31, 2019 and 2018, respectively) are being amortized through 2022. The balance at December 31, 2018 also includes $31 million related to obsolete inventories of certain retired units, which was fully amortized under the 2019 ARP. See "Rate Plans – 2019 ARP" and "Integrated Resource Plan" herein for additional information.

(f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2019, the amortization periods do not exceed 33 years.

(g) Recorded as earned by employees and recovered as paid, generally within one year.

(h) Effective January 1, 2020, Georgia Power is recovering $12 million annually for environmental remediation. See Note 3 under "Environmental Remediation" for additional information.

(i) Recovered through Georgia Power's fuel cost recovery mechanism upon final settlement, within four years.

(j) Comprised of several components including deferred nuclear outage costs and cancelled construction projects. Nuclear outage costs are recorded as incurred and recovered over the outage cycles of each nuclear unit, which do not exceed 24 months. Approximately $22 million of costs associated with construction of environmental controls that will not be completed as a result of unit retirements are being amortized through 2022.

(k) At December 31, 2019 and 2018, includes approximately $110 million and $100 million, respectively, as a result of the retail ROE exceeding the allowed retail ROE range and approximately $105 million and $55 million, respectively, related to the Georgia Power Tax Reform Settlement Agreement. See "Rate Plans" herein for additional information.

(l) Comprised of Demand-Side Management (DSM) tariffs over recovery, building lease, and fuel-hedging gains. DSM tariffs over recovery of $10 million at December 31, 2019 is being amortized through 2022. The building lease is being amortized through 2030. Fuel-hedging gains are refunded through Georgia Power's fuel cost recovery mechanism upon final settlement, within four years.

(m)

Generally not earning a return as they are excluded from rate base or are offset in rate base by a corresponding asset or liability.

Regulatory assets and (liabilities) reflected in the balance sheets of Mississippi Power at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans – regulatory assets	$	213		$	171		(a)
Asset retirement obligations	210			143			(b)
Kemper County energy facility assets, net	61			69			(c)
Remaining net book value of retired assets	30			41			(d)
Property tax	47			44			(e)
Deferred charges related to income taxes	33			34			(b)
Plant Daniel Units 3 and 4	34			36			(f)
ECO Plan carryforward	—			26			(g)
Other regulatory assets	48			28			(h)
Deferred credits related to income taxes	(358		)	(377		)	(i)
Other cost of removal obligations	(189		)	(185		)	(b)
Property damage	(55		)	(56		)	(j)
Other regulatory liabilities	(10		)	(9		)	(k)
Total regulatory assets (liabilities), net	$	64		$	(35	)

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) are approved by the Mississippi PSC and are as follows:

(a) Recovered and amortized over the average remaining service period which may range up to 14 years. See Note 11 for additional information.

(b) Asset retirement and other cost of removal obligations will be settled and trued up upon completion of removal activities over a period to be determined by the Mississippi PSC. Asset retirement and other cost of removal obligations and deferred charges related to income taxes are generally recovered over the related property lives, which may range up to 48 years.

(c) Includes $78 million of regulatory assets and $18 million of regulatory liabilities that are expected to be fully amortized by 2025 and 2023, respectively. For additional information, see "Kemper County Energy Facility – Rate Recovery" herein.

(d) Retail portion includes approximately $16 million being recovered over a five-year period through 2021 and 2022 for Plant Watson and Plant Greene County, respectively. Wholesale portion includes approximately $14 million being recovered over a 12-year period through 2031 for Plant Watson and Plant Greene County.

(e) Recovered through the ad valorem tax adjustment clause over a 12-month period beginning in April of the following year. See "Ad Valorem Tax Adjustment" herein for additional information.

(f) Represents the difference between the revenue requirement under purchase accounting and operating lease accounting, which will be amortized over a 10-year period beginning October 2021.

(g) Generally recovered through the ECO Plan clause in the year following the deferral. See "Environmental Compliance Overview Plan" herein.

(h) Includes $9 million related to vacation pay and $5 million related to other miscellaneous assets, all of which are recorded and recovered over periods not exceeding one year; $6 million related to loss on reacquired debt, which is recorded and amortized over either the remaining life of the original issue, or if refinanced, over the remaining life of the new issue (at December 31, 2019, the amortization periods did not exceed 22 years); and $27 million related to fuel-hedging assets, which are recorded over the life of the underlying hedged purchase contracts, which generally do not exceed three years, and are recovered through Mississippi Power's energy cost management clause upon settlement.

(i) Includes excess deferred income taxes primarily associated with Tax Reform Legislation of $358 million, of which $252 million is related to protected deferred income taxes being recovered over the related property lives, which may range up to 48 years, and $106 million related to unprotected deferred income taxes (not subject to normalization). The unprotected retail portion includes $28 million associated with the Kemper County energy facility being amortized over an eight-year period through 2025. The unprotected wholesale portion includes $18 million of excess deferred income taxes being amortized over three-year periods through 2022. An additional $8 million associated with the System Restoration Rider is being amortized over an eight-year period through 2025. The amortization period for the remaining unprotected deferred income taxes is expected to be determined in the Mississippi Power 2019 Base Rate Case. See "Kemper County Energy Facility" and "Municipal and Rural Associations Tariff" herein and Note 10 for additional information.

(j) See "System Restoration Rider" herein.

(k)

Refunded or amortized generally over periods not exceeding one year.

Regulatory assets and (liabilities) reflected in the balance sheets of Southern Company Gas at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Environmental remediation	$	296		$	311		(a,b)
Retiree benefit plans	167			161			(a,c)
Long-term debt fair value adjustment	107			121			(d)
Under recovered regulatory clause revenues	72			90			(e)
Other regulatory assets	68			59			(f)
Other cost of removal obligations	(1,606		)	(1,585		)	(g)
Deferred income tax credits	(874		)	(940		)	(g,i)
Over recovered regulatory clause revenues	(82		)	(43		)	(e)
Other regulatory liabilities	(22		)	(46		)	(h)
Total regulatory assets (liabilities), net	$	(1,874	)	$	(1,872	)

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) have been approved or accepted by the relevant state PSC or other regulatory body and are as follows:

(a) Not earning a return as offset in rate base by a corresponding asset or liability.

(b) Recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 for additional information.

(c) Recovered and amortized over the average remaining service period which range up to 15 years. See Note 11 for additional information.

(d) Recovered over the remaining life of the original debt issuances at acquisition, which range up to 19 years as of December 31, 2019.

(e) Recorded and recovered or amortized over periods generally not exceeding six years. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have various other cost recovery mechanisms for the recovery of costs, including those related to infrastructure replacement programs.

(f) Includes financial instrument-hedging assets totaling $11 million and $8 million at December 31, 2019 and 2018, respectively, which are recorded over the life of the underlying hedged purchase contracts generally not exceeding two years, vacation pay assets totaling $11 million at both December 31, 2019 and 2018, which are recorded as earned by employees and recovered as paid, generally within one year, and several other miscellaneous components, which are recovered or amortized over periods generally not exceeding eight years.

(g) Other cost of removal obligations are recorded and deferred income tax liabilities are amortized over the related property lives, which may range up to 80 years. Cost of removal liabilities will be settled and trued up following completion of the related activities.

(h) Comprised of numerous components, including amounts to be refunded to customers as a result of the Tax Reform Legislation and energy efficiency programs, which are recovered or amortized over remaining periods generally not exceeding 20 years. Upon final settlement, actual energy efficiency program costs incurred are recovered, and actual income earned is refunded through the energy cost recovery clause. See "Rate Proceedings" herein for additional information regarding customer refunds resulting from the Tax Reform Legislation.

(i) As of December 31, 2019, includes $12 million of excess deferred income tax liabilities not subject to normalization as a result of the Tax Reform Legislation which are being amortized through 2024. See "Rate Proceedings" herein and Note 10 for additional details.

Infrastructure Replacement Programs and Capital Projects

ble illustrates Southern Company Gas' authorized ratemaking amounts that are not recognized on its balance sheets. These amounts are primarily composed of an allowed equity rate of return on assets associated with certain regulatory infrastructure programs. These amounts will be recognized as revenues in Southern Company Gas' financial statements in the periods they are billable to customers, the majority of which will be recovered by 2025.

	December 31, 2019		December 31, 2018
	(in millions)
Atlanta Gas Light	$	70	$	95
Virginia Natural Gas	10		11
Nicor Gas	2		4
Total	$	82	$	110

Schedule of regulatory liabilities

Regulatory assets and (liabilities) reflected in the consolidated balance sheets of Southern Company at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans	$	4,423		$	3,658		(a,o)
Asset retirement obligations-asset	4,381			2,933			(b,o)
Remaining net book value of retired assets	1,275			211			(c)
Deferred income tax charges	803			799			(b,n)
Property damage reserves-asset	410			416			(d)
Environmental remediation-asset	349			366			(e,o)
Loss on reacquired debt	323			346			(f)
Under recovered regulatory clause revenues	254			407			(g)
Vacation pay	186			182			(h,o)
Long-term debt fair value adjustment	107			121			(i)
Other regulatory assets	492			581			(j)
Deferred income tax credits	(6,301		)	(6,455		)	(b,n)
Other cost of removal obligations	(2,084		)	(2,297		)	(b)
Customer refunds	(285		)	(293		)	(k)
Over recovered regulatory clause revenues	(205		)	(47		)	(g)
Property damage reserves-liability	(204		)	(76		)	(l)
Other regulatory liabilities	(86		)	(132		)	(m)
Total regulatory assets (liabilities), net	$	3,838		$	720

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) are approved by the respective PSC or regulatory agency and are as follows:

(a) Recovered and amortized over the average remaining service period, which may range up to 15 years. See Note 11 for additional information.

(b) AROs and other cost of removal obligations are recorded, deferred income tax assets are recovered, and deferred income tax liabilities are amortized over the related property lives, which may range up to 80 years. Asset retirement and removal liabilities will be settled and trued up following completion of the related activities. Included in the deferred income tax assets is $23 million for the retiree Medicare drug subsidy, which is being recovered and amortized through 2027.

(c) Amortized over periods not exceeding 18 years.

(d) Effective January 1, 2020, Georgia Power is recovering approximately $213 million annually for storm damage. See "Georgia Power – Rate Plans – 2019 ARP" and " – Storm Damage Recovery" herein for additional information.

(e) Recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 for additional information.

(f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2019, the remaining amortization periods do not exceed 34 years.

(g) Recorded and recovered or amortized over periods generally not exceeding six years.

(h) Recorded as earned by employees and recovered as paid, generally within one year.

(i) Recovered over the remaining life of the original debt issuances at acquisition, which range up to 19 years as of December 31, 2019.

(j) Comprised of numerous immaterial components including nuclear outage costs, fuel-hedging losses, cancelled construction projects, property tax, and other miscellaneous assets. These costs are amortized over remaining periods generally not exceeding eight years as of December 31, 2019.

(k) At December 31, 2019 and 2018, primarily includes approximately $53 million and $109 million, respectively, at Alabama Power and $110 million and $100 million, respectively, at Georgia Power as a result of each company exceeding its allowed retail return range, as well as approximately $105 million and $55 million, respectively, pursuant to the Georgia Power Tax Reform Settlement Agreement. See "Alabama Power – Rate RSE" and "Georgia Power – Rate Plans" herein for additional information.

(l) Amortized as related expenses are incurred. See "Alabama Power – Rate NDR" and "Mississippi Power – System Restoration Rider" herein for additional information.

(m) Comprised of numerous components including building leases, fuel-hedging gains, and other liabilities that are recovered over remaining periods not exceeding 20 years.

(n) As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization, including $778 million of liabilities being amortized over periods not exceeding six years as of December 31, 2019. See "Georgia Power," "Mississippi Power," and "Southern Company Gas" herein and Note 10 for additional information.

(o)

Not earning a return as offset in rate base by a corresponding asset or liability.

Regulatory assets and (liabilities) reflected in the balance sheets of Alabama Power at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans	$	1,131		$	947		(a,o)
Asset retirement obligations	1,043			147			(b)
Deferred income tax charges	245			241			(b,c,d)
(Over) under recovered regulatory clause revenues	(72		)	176			(e)
Regulatory clauses	142			142			(f)
Vacation pay	72			71			(g,o)
Loss on reacquired debt	52			56			(h)
Nuclear outage	78			49			(i)
Remaining net book value of retired assets	649			43			(j)
Other regulatory assets	67			57			(k,l)
Deferred income tax credits	(1,960		)	(2,027		)	(b,d)
Other cost of removal obligations	(412		)	(497		)	(b)
Customer refunds	(56		)	(142		)	(m)
Natural disaster reserve	(150		)	(20		)	(n)
Other regulatory liabilities	(19		)	(12		)	(l)
Total regulatory assets (liabilities), net	$	810		$	(769	)

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) have been accepted or approved by the Alabama PSC and are as follows:

(a) Recovered and amortized over the average remaining service period which may range up to 14 years. See Note 11 for additional information.

(b) Asset retirement and removal assets and liabilities are recorded, deferred income tax assets are recovered, and deferred income tax credits are amortized over the related property lives, which may range up to 53 years. Asset retirement and other cost of removal assets and liabilities will be settled and trued up following completion of the related activities.

(c) Included in the deferred income tax charges are $9 million for 2019 and $10 million for 2018 for the retiree Medicare drug subsidy, which is being recovered and amortized through 2027.

(d) As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization. The recovery and amortization of these amounts will occur ratably over the related property lives, which may range up to 53 years. See Note 10 for additional information.

(e) Recorded monthly and expected to be recovered or returned within three years. See "Rate CNP PPA," "Rate CNP Compliance," and" Rate ECR" herein for additional information.

(f) In accordance with an accounting order issued in 2017 by the Alabama PSC, these regulatory assets will be amortized concurrently with the effective date of Alabama Power's next depreciation study, which is expected to occur no later than 2022.

(g) Recorded as earned by employees and recovered as paid, generally within one year. This includes both vacation and banked holiday pay.

(h) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2019, the remaining amortization periods do not exceed 30 years.

(i) Nuclear outage costs are deferred to a regulatory asset when incurred and amortized over a subsequent 18-month period.

(j) Recorded and amortized over remaining periods not exceeding 18 years.

(k) Comprised of components including generation site selection/evaluation costs, which are capitalized upon initiation of related construction projects, if applicable, and PPA capacity costs, which are to be recovered over the next 12 months.

(l) Fuel-hedging assets and liabilities are recorded over the life of the underlying hedged purchase contracts, which generally do not exceed three and a half years. Upon final settlement, actual costs incurred are recovered through the energy cost recovery clause.

(m) Includes $53 million for 2019 and $109 million for 2018 due to the retail return exceeding the allowed range. The December 31, 2018 balance also includes a $33 million excess deferred tax liability used to increase the Rate NDR balance in 2019. See "Rate RSE," "Rate NDR," and "Tax Reform Accounting Order" herein for additional information.

(n) Amortized as expenses are incurred. See "Rate NDR" herein for additional information.

(o)

Not earning a return as offset in rate base by a corresponding asset or liability.

Regulatory assets and (liabilities) reflected in the balance sheets of Georgia Power at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans	$	1,516		$	1,295		(a, m)
Asset retirement obligations	3,119			2,644			(b, m)
Deferred income tax charges	523			522			(b, c, m)
Storm damage reserves	410			416			(d)
Remaining net book value of retired assets	596			127			(e)
Loss on reacquired debt	262			277			(f, m)
Vacation pay	93			91			(g, m)
Other cost of removal obligations	156			68			(b)
Environmental remediation	52			55			(h)
Fuel-hedging (realized and unrealized) losses	53			15			(i, m)
Other regulatory assets	50			120			(j)
Deferred income tax credits	(3,078		)	(3,080		)	(b, c)
Customer refunds	(229		)	(165		)	(k)
Other regulatory liabilities	(16		)	(7		)	(l, m)
Total regulatory assets (liabilities), net	$	3,507		$	2,378

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) are approved by the Georgia PSC and are as follows:

(a) Recovered and amortized over the average remaining service period which may range up to 13 years. See Note 11 for additional information.

(b) Effective January 1, 2020, Georgia Power is recovering CCR AROs through its Environmental Compliance Cost Recovery (ECCR) tariff and approximately $5 million annually for other AROs through its traditional base tariffs. See "Rate Plans – 2019 ARP" and "Integrated Resource Plan" herein for additional information on recovery of compliance costs for CCR AROs. Other cost of removal obligations, non-CCR AROs, and deferred income tax assets are recovered and deferred income tax liabilities are amortized over the related property lives, which may range up to 60 years. Included in the deferred income tax assets is $13 million for the retiree Medicare drug subsidy, which is being recovered and amortized through 2022. See Note 6 for additional information on AROs.

(c) As a result of the Tax Reform Legislation, these balances include $145 million of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 and approximately $660 million of deferred income tax liabilities, neither of which are subject to normalization. The recovery of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 is expected to be determined in a future regulatory proceeding. Effective January 1, 2020, the deferred income tax liabilities are being amortized through 2022. See "Rate Plans" herein and Note 10 for additional information.

(d) Effective January 1, 2020, Georgia Power is recovering $213 million annually for storm damage. See "Rate Plans – 2019 ARP" and "Storm Damage Recovery" herein and Note 1 under "Storm Damage Reserves" for additional information.

(e) The net book values of Plant Hammond Units 1 through 4 ($488 million at December 31, 2019) and Plant Branch Units 1 through 4 ($69 million and $87 million at December 31, 2019 and 2018, respectively) are being amortized over the units' remaining useful lives, which vary between 2020 and 2035. The net book values of Plant McIntosh Unit 1 ($30 million at December 31, 2019) and Plant Mitchell Unit 3 ($8 million and $9 million at December 31, 2019 and 2018, respectively) are being amortized through 2022. The balance at December 31, 2018 also includes $31 million related to obsolete inventories of certain retired units, which was fully amortized under the 2019 ARP. See "Rate Plans – 2019 ARP" and "Integrated Resource Plan" herein for additional information.

(f) Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2019, the amortization periods do not exceed 33 years.

(g) Recorded as earned by employees and recovered as paid, generally within one year.

(h) Effective January 1, 2020, Georgia Power is recovering $12 million annually for environmental remediation. See Note 3 under "Environmental Remediation" for additional information.

(i) Recovered through Georgia Power's fuel cost recovery mechanism upon final settlement, within four years.

(j) Comprised of several components including deferred nuclear outage costs and cancelled construction projects. Nuclear outage costs are recorded as incurred and recovered over the outage cycles of each nuclear unit, which do not exceed 24 months. Approximately $22 million of costs associated with construction of environmental controls that will not be completed as a result of unit retirements are being amortized through 2022.

(k) At December 31, 2019 and 2018, includes approximately $110 million and $100 million, respectively, as a result of the retail ROE exceeding the allowed retail ROE range and approximately $105 million and $55 million, respectively, related to the Georgia Power Tax Reform Settlement Agreement. See "Rate Plans" herein for additional information.

(l) Comprised of Demand-Side Management (DSM) tariffs over recovery, building lease, and fuel-hedging gains. DSM tariffs over recovery of $10 million at December 31, 2019 is being amortized through 2022. The building lease is being amortized through 2030. Fuel-hedging gains are refunded through Georgia Power's fuel cost recovery mechanism upon final settlement, within four years.

(m)

Generally not earning a return as they are excluded from rate base or are offset in rate base by a corresponding asset or liability.

Regulatory assets and (liabilities) reflected in the balance sheets of Mississippi Power at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Retiree benefit plans – regulatory assets	$	213		$	171		(a)
Asset retirement obligations	210			143			(b)
Kemper County energy facility assets, net	61			69			(c)
Remaining net book value of retired assets	30			41			(d)
Property tax	47			44			(e)
Deferred charges related to income taxes	33			34			(b)
Plant Daniel Units 3 and 4	34			36			(f)
ECO Plan carryforward	—			26			(g)
Other regulatory assets	48			28			(h)
Deferred credits related to income taxes	(358		)	(377		)	(i)
Other cost of removal obligations	(189		)	(185		)	(b)
Property damage	(55		)	(56		)	(j)
Other regulatory liabilities	(10		)	(9		)	(k)
Total regulatory assets (liabilities), net	$	64		$	(35	)

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) are approved by the Mississippi PSC and are as follows:

(a) Recovered and amortized over the average remaining service period which may range up to 14 years. See Note 11 for additional information.

(b) Asset retirement and other cost of removal obligations will be settled and trued up upon completion of removal activities over a period to be determined by the Mississippi PSC. Asset retirement and other cost of removal obligations and deferred charges related to income taxes are generally recovered over the related property lives, which may range up to 48 years.

(c) Includes $78 million of regulatory assets and $18 million of regulatory liabilities that are expected to be fully amortized by 2025 and 2023, respectively. For additional information, see "Kemper County Energy Facility – Rate Recovery" herein.

(d) Retail portion includes approximately $16 million being recovered over a five-year period through 2021 and 2022 for Plant Watson and Plant Greene County, respectively. Wholesale portion includes approximately $14 million being recovered over a 12-year period through 2031 for Plant Watson and Plant Greene County.

(e) Recovered through the ad valorem tax adjustment clause over a 12-month period beginning in April of the following year. See "Ad Valorem Tax Adjustment" herein for additional information.

(f) Represents the difference between the revenue requirement under purchase accounting and operating lease accounting, which will be amortized over a 10-year period beginning October 2021.

(g) Generally recovered through the ECO Plan clause in the year following the deferral. See "Environmental Compliance Overview Plan" herein.

(h) Includes $9 million related to vacation pay and $5 million related to other miscellaneous assets, all of which are recorded and recovered over periods not exceeding one year; $6 million related to loss on reacquired debt, which is recorded and amortized over either the remaining life of the original issue, or if refinanced, over the remaining life of the new issue (at December 31, 2019, the amortization periods did not exceed 22 years); and $27 million related to fuel-hedging assets, which are recorded over the life of the underlying hedged purchase contracts, which generally do not exceed three years, and are recovered through Mississippi Power's energy cost management clause upon settlement.

(i) Includes excess deferred income taxes primarily associated with Tax Reform Legislation of $358 million, of which $252 million is related to protected deferred income taxes being recovered over the related property lives, which may range up to 48 years, and $106 million related to unprotected deferred income taxes (not subject to normalization). The unprotected retail portion includes $28 million associated with the Kemper County energy facility being amortized over an eight-year period through 2025. The unprotected wholesale portion includes $18 million of excess deferred income taxes being amortized over three-year periods through 2022. An additional $8 million associated with the System Restoration Rider is being amortized over an eight-year period through 2025. The amortization period for the remaining unprotected deferred income taxes is expected to be determined in the Mississippi Power 2019 Base Rate Case. See "Kemper County Energy Facility" and "Municipal and Rural Associations Tariff" herein and Note 10 for additional information.

(j)

See "System Restoration Rider" herein.

Regulatory assets and (liabilities) reflected in the balance sheets of Southern Company Gas at December 31, 2019 and 2018 relate to:

	2019			2018			Note
	(in millions)
Environmental remediation	$	296		$	311		(a,b)
Retiree benefit plans	167			161			(a,c)
Long-term debt fair value adjustment	107			121			(d)
Under recovered regulatory clause revenues	72			90			(e)
Other regulatory assets	68			59			(f)
Other cost of removal obligations	(1,606		)	(1,585		)	(g)
Deferred income tax credits	(874		)	(940		)	(g,i)
Over recovered regulatory clause revenues	(82		)	(43		)	(e)
Other regulatory liabilities	(22		)	(46		)	(h)
Total regulatory assets (liabilities), net	$	(1,874	)	$	(1,872	)

Note: Unless otherwise noted, the recovery and amortization periods for these regulatory assets and (liabilities) have been approved or accepted by the relevant state PSC or other regulatory body and are as follows:

(a) Not earning a return as offset in rate base by a corresponding asset or liability.

(b) Recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 for additional information.

(c) Recovered and amortized over the average remaining service period which range up to 15 years. See Note 11 for additional information.

(d) Recovered over the remaining life of the original debt issuances at acquisition, which range up to 19 years as of December 31, 2019.

(e) Recorded and recovered or amortized over periods generally not exceeding six years. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have various other cost recovery mechanisms for the recovery of costs, including those related to infrastructure replacement programs.

(f) Includes financial instrument-hedging assets totaling $11 million and $8 million at December 31, 2019 and 2018, respectively, which are recorded over the life of the underlying hedged purchase contracts generally not exceeding two years, vacation pay assets totaling $11 million at both December 31, 2019 and 2018, which are recorded as earned by employees and recovered as paid, generally within one year, and several other miscellaneous components, which are recovered or amortized over periods generally not exceeding eight years.

(g) Other cost of removal obligations are recorded and deferred income tax liabilities are amortized over the related property lives, which may range up to 80 years. Cost of removal liabilities will be settled and trued up following completion of the related activities.

(h) Comprised of numerous components, including amounts to be refunded to customers as a result of the Tax Reform Legislation and energy efficiency programs, which are recovered or amortized over remaining periods generally not exceeding 20 years. Upon final settlement, actual energy efficiency program costs incurred are recovered, and actual income earned is refunded through the energy cost recovery clause. See "Rate Proceedings" herein for additional information regarding customer refunds resulting from the Tax Reform Legislation.

(i)

As of December 31, 2019, includes $12 million of excess deferred income tax liabilities not subject to normalization as a result of the Tax Reform Legislation which are being amortized through 2024. See "Rate Proceedings" herein and Note 10 for additional details.

Schedule of revised cost and schedule

Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4 by the expected in-service dates of November 2021 and November 2022, respectively, is as follows:

	(in billions)
Base project capital cost forecast(a)(b)	$	8.2
Construction contingency estimate	0.2
Total project capital cost forecast(a)(b)	8.4
Net investment as of December 31, 2019(b)	(5.9		)
Remaining estimate to complete(a)	$	2.5

(a) Excludes financing costs expected to be capitalized through AFUDC of approximately $300 million, of which $23 million had been accrued through December 31, 2019.

(b)

Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds.

Public utilities general disclosures

On December 17, 2019, the Georgia PSC voted to approve the 2019 ARP, under which Georgia Power increased its rates on January 1, 2020 and will increase rates annually for 2021 and 2022 as detailed below based on compliance filings to be made at least 90 days prior to the effective date. Georgia Power will recover estimated increases through its existing tariffs as follows:

Tariff	2020		2021		2022
	(in millions)
Traditional base	$	—	$	120	$	192
ECCR(a)	318		55		184
DSM	12		1		1
Municipal Franchise Fee	12		4		9
Total(b)	$	342	$	181	$	386

(a) Effective January 1, 2020, CCR AROs will be recovered through the ECCR tariff. See "Integrated Resource Plan" herein for additional information on recovery of compliance costs for CCR AROs.

(b)

Totals may not add due to rounding.