Regulatory Matters (Tables)

9 Months Ended

Sep. 30, 2018

Regulated Operations [Abstract]

Public Utilities General Disclosures [Table Text Block]

The following table presents authorized amounts capitalized for ratemaking purposes related to earnings on shareholders’ investment that are not recognized for financial reporting purposes on Exelon's and the Utility Registrant's Consolidated Balance Sheets. These amounts will be recognized as revenues in the related Consolidated Statements of Operations and Comprehensive Income in the periods they are billable to our customers.

	Exelon		ComEd(a)		PECO		BGE(b)		PHI		Pepco(c)		DPL(c)		ACE
September 30, 2018	$	67	$	8	$	—	$	50	$	9	$	5	$	4	$	—
	Exelon		ComEd(a)		PECO		BGE(b)		PHI		Pepco(c)		DPL(c)		ACE
December 31, 2017	$	69	$	6	$	—	$	53	$	10	$	6	$	4	$	—

_________

(a) Reflects ComEd's unrecognized equity returns earned for ratemaking purposes on its electric distribution formula rate regulatory assets.

(b) BGE's authorized amounts capitalized for ratemaking purposes primarily relate to earnings on shareholders' investment on its AMI programs.

(c) Pepco's and DPL's authorized amounts capitalized for ratemaking purposes relate to earnings on shareholders' investment on their respective AMI Programs and Energy Efficiency and Demand Response Programs. The earnings on energy efficiency are on Pepco DC and DPL DE programs only.

	2018
Annual Transmission Updates(a)(b)	ComEd			BGE			Pepco			DPL			ACE
Initial revenue requirement (decrease) increase	$	(44	)	$	10		$	6		$	14		$	4
Annual reconciliation increase (decrease)	18			4			2			13			(4		)
Dedicated facilities increase(c)	—			12			—			—			—
Total revenue requirement (decrease) increase	$	(26	)	$	26		$	8		$	27		$	—
Allowed return on rate base(d)	8.32		%	7.61		%	7.82		%	7.29		%	8.02		%
Allowed ROE(e)	11.50		%	10.50		%	10.50		%	10.50		%	10.50		%

Schedule of Regulatory Assets

he following tables provide information about the regulatory assets and liabilities of Exelon and the Utility Registrants as of September 30, 2018 and December 31, 2017. See Note 3 — Regulatory Matters of the Exelon 2017 Form 10-K for additional information on the specific regulatory assets and liabilities.

September 30, 2018	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory assets
Pension and other postretirement benefits(a)	$	3,710	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes	391		—		381		—		10		10		—		—
AMI programs(c)	583		142		27		198		216		144		72		—
Electric distribution formula rate(d)	228		228		—		—		—		—		—		—
Energy efficiency costs	357		357		—		—		—		—		—		—
Debt costs	102		34		1		11		68		15		7		6
Fair value of long-term debt	716		—		—		—		581		—		—		—
Fair value of PHI's unamortized energy contracts	600		—		—		—		600		—		—		—
Asset retirement obligations	114		76		22		15		1		1		—		—
MGP remediation costs	318		299		19		—		—		—		—		—
Under-recovered uncollectible accounts	71		71		—		—		—		—		—		—
Renewable energy	260		259		—		—		1		—		—		1
Energy and transmission programs(e)(f)(g)(h)(i)(j)	251		7		50		72		122		93		15		14
Deferred storm costs	45		—		—		—		45		11		5		29
Energy efficiency and demand response programs	561		—		2		291		268		194		74		—
Merger integration costs(k)(l)(m)	44		—		—		4		40		18		12		10
Under-recovered revenue decoupling(n)	64		—		—		—		64		64		—		—
COPCO acquisition adjustment	3		—		—		—		3		—		3		—
Workers compensation and long-term disability costs	36		—		—		—		36		36		—		—
Vacation accrual	24		—		11		—		13		—		8		5
Securitized stranded costs	57		—		—		—		57		—		—		57
CAP arrearage	10		—		10		—		—		—		—		—
Removal costs	555		—		—		—		555		156		97		302
DC PLUG charge	168		—		—		—		168		168		—		—
Other	74		12		9		6		47		36		8		3
Total regulatory assets	9,342		1,485		532		597		2,895		946		301		427
Less: current portion	1,340		256		84		195		521		284		66		44
Total noncurrent regulatory assets	$	8,002	$	1,229	$	448	$	402	$	2,374	$	662	$	235	$	383

September 30, 2018	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory liabilities
Other postretirement benefits	$	20	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes(b)	5,054		2,418		—		1,015		1,621		734		493		394
Nuclear decommissioning	2,958		2,469		489		—		—		—		—		—
Removal costs	1,566		1,370		—		67		129		20		109		—
Deferred rent	34		—		—		—		34		—		—		—
Energy efficiency and demand response programs	10		3		5		—		2		—		—		2
DLC program costs	7		—		7		—		—		—		—		—
Electric distribution tax repairs	10		—		10		—		—		—		—		—
Gas distribution tax repairs	4		—		4		—		—		—		—		—
Energy and transmission programs(e)(f)(g)(h)(i)(j)	372		204		143		7		18		—		14		4
Over-recovered revenue decoupling(n)	21		—		—		17		4		—		4		—
Renewable portfolio standards costs	140		140		—		—		—		—		—		—
Zero emission credit costs	18		18		—		—		—		—		—		—
Over-recovered uncollectible accounts	2		—		—		—		2		—		—		2
Merger integration costs(l)	3		—		—		—		3		—		3		—
TCJA income tax benefit over-recoveries(o)	108		—		61		19		28		6		8		14
Other	118		16		21		40		41		4		23		12
Total regulatory liabilities	10,445		6,638		740		1,165		1,882		764		654		428
Less: current portion	689		320		159		95		99		5		67		27
Total noncurrent regulatory liabilities	$	9,756	$	6,318	$	581	$	1,070	$	1,783	$	759	$	587	$	401

December 31, 2017	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory assets
Pension and other postretirement benefits(a)	$	3,848	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes	306		—		297		—		9		9		—		—
AMI programs(c)	640		155		36		214		235		158		77		—
Electric distribution formula rate(d)	244		244		—		—		—		—		—		—
Energy efficiency costs	166		166		—		—		—		—		—		—
Debt costs	116		37		1		11		73		15		8		5
Fair value of long-term debt	758		—		—		—		619		—		—		—
Fair value of PHI's unamortized energy contracts	750		—		—		—		750		—		—		—
Asset retirement obligations	109		73		22		14		—		—		—		—
MGP remediation costs	295		273		22		—		—		—		—		—
Under-recovered uncollectible accounts	61		61		—		—		—		—		—		—
Renewable energy	258		256		—		—		2		—		1		1
Energy and transmission programs(e)(g)(h)(i)(j)	82		6		1		23		52		11		15		26
Deferred storm costs	27		—		—		—		27		7		5		15
Energy efficiency and demand response programs	596		—		1		285		310		229		81		—
Merger integration costs(k)(l)(m)	45		—		—		6		39		20		10		9
Under-recovered revenue decoupling(n)	55		—		—		14		41		38		3		—
COPCO acquisition adjustment	5		—		—		—		5		—		5		—
Workers compensation and long-term disability costs	35		—		—		—		35		35		—		—
Vacation accrual	19		—		6		—		13		—		8		5
Securitized stranded costs	79		—		—		—		79		—		—		79
CAP arrearage	8		—		8		—		—		—		—		—
Removal costs	529		—		—		—		529		150		93		286
DC PLUG charge	190		—		—		—		190		190		—		—
Other	67		8		16		4		39		29		8		4
Total regulatory assets	9,288		1,279		410		571		3,047		891		314		430
Less: current portion	1,267		225		29		174		554		213		69		71
Total noncurrent regulatory assets	$	8,021	$	1,054	$	381	$	397	$	2,493	$	678	$	245	$	359

December 31, 2017	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory liabilities
Other postretirement benefits	$	30	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes(b)	5,241		2,479		—		1,032		1,730		809		510		411
Nuclear decommissioning	3,064		2,528		536		—		—		—		—		—
Removal costs	1,573		1,338		—		105		130		20		110		—
Deferred rent	36		—		—		—		36		—		—		—
Energy efficiency and demand response programs	23		4		19		—		—		—		—		—
DLC program costs	7		—		7		—		—		—		—		—
Electric distribution tax repairs	35		—		35		—		—		—		—		—
Gas distribution tax repairs	9		—		9		—		—		—		—		—
Energy and transmission programs(e)(f)(i)(j)	111		47		60		—		4		—		1		3
Renewable portfolio standard costs	63		63		—		—		—		—		—		—
Zero emission credit costs	112		112		—		—		—		—		—		—
Over-recovered uncollectible accounts	2		—		—		—		2		—		—		2
Other	82		6		24		26		26		3		14		6
Total regulatory liabilities	10,388		6,577		690		1,163		1,928		832		635		422
Less: current portion	523		249		141		62		56		3		42		11
Total noncurrent regulatory liabilities	$	9,865	$	6,328	$	549	$	1,101	$	1,872	$	829	$	593	$	411

__________

(a) Includes regulatory assets established at the Constellation and PHI merger dates of $401 million and $897 million, respectively, as of September 30, 2018 and $440 million and $953 million, respectively, as of December 31, 2017 related to the rate regulated portions of the deferred costs associated with legacy Constellation’s and PHI’s pension and other postretirement benefit plans that are being amortized and recovered over approximately 12 years and 3 to 15 years, respectively (as established at the respective acquisition dates). The Utility Registrants are not earning or paying a return on these amounts.

(b) As of September 30, 2018, includes transmission-related income tax regulatory liabilities that require FERC approval separate from the transmission formula rate of $464 million, $135 million, $136 million, $145 million and $141 million for ComEd, BGE, Pepco, DPL and ACE, respectively. As of December 31, 2017, includes transmission-related income tax regulatory liabilities that require FERC approval separate from the transmission formula rate of $484 million, $137 million, $147 million, $148 million and $147 million for ComEd, BGE, Pepco, DPL and ACE, respectively.

(c) As of September 30, 2018, BGE's regulatory asset of $198 million includes $117 million of unamortized incremental deployment costs under the program, $48 million of unamortized costs of the non-AMI meters replaced under the AMI program, and $33 million related to post-test year incremental program deployment costs incurred prior to approval became effective June 2016. As of December 31, 2017, BGE's regulatory asset of $214 million includes $129 million of unamortized incremental deployment costs under the program, $53 million of unamortized costs of the non-AMI meters replaced under the AMI program, and $32 million related to post-test year incremental program deployment costs incurred prior to approval became effective June 2016. Recovery of the post-test year incremental deployment costs will be addressed in a future base rate proceeding.

(d) As of September 30, 2018, ComEd’s regulatory asset of $228 million was comprised of $165 million for the 2016, 2017 and 2018 annual reconciliations and $63 million related to significant one-time events. As of December 31, 2017, ComEd’s regulatory asset of $244 million was comprised of $186 million for the 2016 and 2017 annual reconciliations and $58 million related to significant one-time events.

(e) As of September 30, 2018, ComEd’s regulatory asset of $7 million represents transmission costs recoverable through its FERC approved formula rate. As of September 30, 2018, ComEd’s regulatory liability of $204 million included $101 million related to the PJM Transmission Rate Design Settlement, $72 million related to over-recovered energy costs and $31 million associated with revenues received for renewable energy requirements. As of December 31, 2017, ComEd’s regulatory asset of $6 million represents transmission costs recoverable through its FERC approved formula rate. As of December 31, 2017, ComEd’s regulatory liability of $47 million included $14 million related to over-recovered energy costs and $33 million associated with revenues received for renewable energy requirements.

(f) As of September 30, 2018, PECO’s regulatory asset of $50 million represents the under-recovered natural gas costs under the PGC. As of December 31, 2017, PECO’s regulatory asset of $1 million is related to under-recovered costs under the TSC program. As of September 30, 2018, PECO's regulatory liability of $143 million included $85 million related to the PJM Transmission Rate Design Settlement, $43 million related to over-recovered costs under the DSP program, $3 million related to the over-recovered transmission service charges and $12 million related to over-recovered non-bypassable transmission service charges. As of December 31, 2017, PECO's regulatory liability of $60 million included $36 million related to over-recovered costs under the DSP program, $12 million related to over-recovered non-bypassable transmission service charges and $12 million related to the over-recovered natural gas costs under the PGC.

(g) As of September 30, 2018, BGE's regulatory asset of $72 million included $48 million related to the PJM Transmission Rate Design Settlement, $14 million of costs associated with transmission costs recoverable through its FERC approved formula rate, $7 million related to under-recovered electric energy costs and $3 million of abandonment costs to be recovered upon FERC approval. As of September 30, 2018, BGE's regulatory liability of $7 million related to over-recovered natural gas costs. As of December 31, 2017, BGE’s regulatory asset of $23 million included $7 million of costs associated with transmission costs recoverable through its FERC approved formula rate, $5 million related to under-recovered electric energy costs, $3 million of abandonment costs to be recovered upon FERC approval and $8 million of under-recovered natural gas costs.

(h) As of September 30, 2018, Pepco's regulatory asset of $93 million included $74 million related to the PJM Transmission Rate Design Settlement, $7 million of transmission costs recoverable through its FERC approved formula rate and $12 million related to under-recovered electric energy costs. As of December 31, 2017, Pepco's regulatory asset of $11 million included $3 million of transmission costs recoverable through its FERC approved formula rate and $8 million of under-recovered electric energy costs.

(i) As of September 30, 2018, DPL's regulatory asset of $15 million included $14 million of transmission costs recoverable through its FERC approved formula rate and $1 million related to under-recovered electric energy costs. As of September 30, 2018, DPL's regulatory liability of $14 million included $10 million related to the PJM Transmission Rate Design Settlement and $4 million related to over-recovered electric energy and gas fuel costs. As of December 31, 2017, DPL's regulatory asset of $15 million included $8 million of transmission costs recoverable through its FERC approved formula rate and $7 million related to under-recovered electric energy costs. As of December 31, 2017, DPL's regulatory liability of $1 million related to over-recovered electric energy costs.

(j) As of September 30, 2018, ACE's regulatory asset of $14 million included $7 million of transmission costs recoverable through its FERC approved formula rate and $7 million of under-recovered electric energy costs. As of September 30, 2018, ACE's regulatory liability of $4 million included $3 million related to the PJM Transmission Rate Design Settlement and $1 million related to over-recovered electric energy costs. As of December 31, 2017, ACE's regulatory asset of $26 million included $11 million of transmission costs recoverable through its FERC approved formula rate and $15 million of under-recovered electric energy costs. As of December 31, 2017, ACE's regulatory liability of $3 million related to over-recovered electric energy costs.

(k) As of September 30, 2018, Pepco’s regulatory asset of $18 million represents previously incurred PHI integration costs, including $9 million authorized for recovery in Maryland and $9 million expected to be recovered in the District of Columbia service territory. As of December 31, 2017, Pepco’s regulatory asset of $20 million represents previously incurred PHI integration costs, including $11 million authorized for recovery in Maryland and $9 million expected to be recovered in the District of Columbia service territory.

(l) As of September 30, 2018, DPL’s regulatory asset of $12 million represents previously incurred PHI integration costs, including $4 million authorized for recovery in Maryland, $5 million authorized for recovery in Delaware electric rates, $2 million authorized for recovery in Delaware gas rates and $1 million expected to be recovered in electric rates in the Delaware and Maryland service territories. As of September 30, 2018, DPL’s regulatory liability of $3 million represents net synergy savings incurred related to PHI integration costs that are expected to be returned in electric and gas rates in the Delaware service territory. As of December 31, 2017, DPL’s regulatory asset of $10 million represents previously incurred PHI integration costs, including $4 million authorized for recovery in Maryland, $5 million authorized for recovery in Delaware electric rates, and $1 million expected to be recovered in electric and gas rates in the Maryland and Delaware service territories.

(m) As of September 30, 2018 and December 31, 2017, ACE’s regulatory asset of $10 million and $9 million, respectively, represents previously incurred PHI integration costs expected to be recovered in the New Jersey service territory.

(n) Represents the electric and natural gas distribution costs recoverable from customers under BGE’s decoupling mechanism. As of September 30, 2018, BGE had a regulatory asset of less than $1 million related to under-recovered electric revenue decoupling and a regulatory liability of $17 million related to over-recovered natural gas revenue decoupling. As of December 31, 2017, BGE had a regulatory asset of $10 million related to under-recovered electric revenue decoupling and $4 million related to under-recovered natural gas revenue decoupling.

Schedule of Regulatory Liabilities

he following tables provide information about the regulatory assets and liabilities of Exelon and the Utility Registrants as of September 30, 2018 and December 31, 2017. See Note 3 — Regulatory Matters of the Exelon 2017 Form 10-K for additional information on the specific regulatory assets and liabilities.

September 30, 2018	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory assets
Pension and other postretirement benefits(a)	$	3,710	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes	391		—		381		—		10		10		—		—
AMI programs(c)	583		142		27		198		216		144		72		—
Electric distribution formula rate(d)	228		228		—		—		—		—		—		—
Energy efficiency costs	357		357		—		—		—		—		—		—
Debt costs	102		34		1		11		68		15		7		6
Fair value of long-term debt	716		—		—		—		581		—		—		—
Fair value of PHI's unamortized energy contracts	600		—		—		—		600		—		—		—
Asset retirement obligations	114		76		22		15		1		1		—		—
MGP remediation costs	318		299		19		—		—		—		—		—
Under-recovered uncollectible accounts	71		71		—		—		—		—		—		—
Renewable energy	260		259		—		—		1		—		—		1
Energy and transmission programs(e)(f)(g)(h)(i)(j)	251		7		50		72		122		93		15		14
Deferred storm costs	45		—		—		—		45		11		5		29
Energy efficiency and demand response programs	561		—		2		291		268		194		74		—
Merger integration costs(k)(l)(m)	44		—		—		4		40		18		12		10
Under-recovered revenue decoupling(n)	64		—		—		—		64		64		—		—
COPCO acquisition adjustment	3		—		—		—		3		—		3		—
Workers compensation and long-term disability costs	36		—		—		—		36		36		—		—
Vacation accrual	24		—		11		—		13		—		8		5
Securitized stranded costs	57		—		—		—		57		—		—		57
CAP arrearage	10		—		10		—		—		—		—		—
Removal costs	555		—		—		—		555		156		97		302
DC PLUG charge	168		—		—		—		168		168		—		—
Other	74		12		9		6		47		36		8		3
Total regulatory assets	9,342		1,485		532		597		2,895		946		301		427
Less: current portion	1,340		256		84		195		521		284		66		44
Total noncurrent regulatory assets	$	8,002	$	1,229	$	448	$	402	$	2,374	$	662	$	235	$	383

September 30, 2018	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory liabilities
Other postretirement benefits	$	20	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes(b)	5,054		2,418		—		1,015		1,621		734		493		394
Nuclear decommissioning	2,958		2,469		489		—		—		—		—		—
Removal costs	1,566		1,370		—		67		129		20		109		—
Deferred rent	34		—		—		—		34		—		—		—
Energy efficiency and demand response programs	10		3		5		—		2		—		—		2
DLC program costs	7		—		7		—		—		—		—		—
Electric distribution tax repairs	10		—		10		—		—		—		—		—
Gas distribution tax repairs	4		—		4		—		—		—		—		—
Energy and transmission programs(e)(f)(g)(h)(i)(j)	372		204		143		7		18		—		14		4
Over-recovered revenue decoupling(n)	21		—		—		17		4		—		4		—
Renewable portfolio standards costs	140		140		—		—		—		—		—		—
Zero emission credit costs	18		18		—		—		—		—		—		—
Over-recovered uncollectible accounts	2		—		—		—		2		—		—		2
Merger integration costs(l)	3		—		—		—		3		—		3		—
TCJA income tax benefit over-recoveries(o)	108		—		61		19		28		6		8		14
Other	118		16		21		40		41		4		23		12
Total regulatory liabilities	10,445		6,638		740		1,165		1,882		764		654		428
Less: current portion	689		320		159		95		99		5		67		27
Total noncurrent regulatory liabilities	$	9,756	$	6,318	$	581	$	1,070	$	1,783	$	759	$	587	$	401

December 31, 2017	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory assets
Pension and other postretirement benefits(a)	$	3,848	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes	306		—		297		—		9		9		—		—
AMI programs(c)	640		155		36		214		235		158		77		—
Electric distribution formula rate(d)	244		244		—		—		—		—		—		—
Energy efficiency costs	166		166		—		—		—		—		—		—
Debt costs	116		37		1		11		73		15		8		5
Fair value of long-term debt	758		—		—		—		619		—		—		—
Fair value of PHI's unamortized energy contracts	750		—		—		—		750		—		—		—
Asset retirement obligations	109		73		22		14		—		—		—		—
MGP remediation costs	295		273		22		—		—		—		—		—
Under-recovered uncollectible accounts	61		61		—		—		—		—		—		—
Renewable energy	258		256		—		—		2		—		1		1
Energy and transmission programs(e)(g)(h)(i)(j)	82		6		1		23		52		11		15		26
Deferred storm costs	27		—		—		—		27		7		5		15
Energy efficiency and demand response programs	596		—		1		285		310		229		81		—
Merger integration costs(k)(l)(m)	45		—		—		6		39		20		10		9
Under-recovered revenue decoupling(n)	55		—		—		14		41		38		3		—
COPCO acquisition adjustment	5		—		—		—		5		—		5		—
Workers compensation and long-term disability costs	35		—		—		—		35		35		—		—
Vacation accrual	19		—		6		—		13		—		8		5
Securitized stranded costs	79		—		—		—		79		—		—		79
CAP arrearage	8		—		8		—		—		—		—		—
Removal costs	529		—		—		—		529		150		93		286
DC PLUG charge	190		—		—		—		190		190		—		—
Other	67		8		16		4		39		29		8		4
Total regulatory assets	9,288		1,279		410		571		3,047		891		314		430
Less: current portion	1,267		225		29		174		554		213		69		71
Total noncurrent regulatory assets	$	8,021	$	1,054	$	381	$	397	$	2,493	$	678	$	245	$	359

December 31, 2017	Exelon		ComEd		PECO		BGE		PHI		Pepco		DPL		ACE
Regulatory liabilities
Other postretirement benefits	$	30	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Deferred income taxes(b)	5,241		2,479		—		1,032		1,730		809		510		411
Nuclear decommissioning	3,064		2,528		536		—		—		—		—		—
Removal costs	1,573		1,338		—		105		130		20		110		—
Deferred rent	36		—		—		—		36		—		—		—
Energy efficiency and demand response programs	23		4		19		—		—		—		—		—
DLC program costs	7		—		7		—		—		—		—		—
Electric distribution tax repairs	35		—		35		—		—		—		—		—
Gas distribution tax repairs	9		—		9		—		—		—		—		—
Energy and transmission programs(e)(f)(i)(j)	111		47		60		—		4		—		1		3
Renewable portfolio standard costs	63		63		—		—		—		—		—		—
Zero emission credit costs	112		112		—		—		—		—		—		—
Over-recovered uncollectible accounts	2		—		—		—		2		—		—		2
Other	82		6		24		26		26		3		14		6
Total regulatory liabilities	10,388		6,577		690		1,163		1,928		832		635		422
Less: current portion	523		249		141		62		56		3		42		11
Total noncurrent regulatory liabilities	$	9,865	$	6,328	$	549	$	1,101	$	1,872	$	829	$	593	$	411

__________

(a) Includes regulatory assets established at the Constellation and PHI merger dates of $401 million and $897 million, respectively, as of September 30, 2018 and $440 million and $953 million, respectively, as of December 31, 2017 related to the rate regulated portions of the deferred costs associated with legacy Constellation’s and PHI’s pension and other postretirement benefit plans that are being amortized and recovered over approximately 12 years and 3 to 15 years, respectively (as established at the respective acquisition dates). The Utility Registrants are not earning or paying a return on these amounts.

(b) As of September 30, 2018, includes transmission-related income tax regulatory liabilities that require FERC approval separate from the transmission formula rate of $464 million, $135 million, $136 million, $145 million and $141 million for ComEd, BGE, Pepco, DPL and ACE, respectively. As of December 31, 2017, includes transmission-related income tax regulatory liabilities that require FERC approval separate from the transmission formula rate of $484 million, $137 million, $147 million, $148 million and $147 million for ComEd, BGE, Pepco, DPL and ACE, respectively.

(c) As of September 30, 2018, BGE's regulatory asset of $198 million includes $117 million of unamortized incremental deployment costs under the program, $48 million of unamortized costs of the non-AMI meters replaced under the AMI program, and $33 million related to post-test year incremental program deployment costs incurred prior to approval became effective June 2016. As of December 31, 2017, BGE's regulatory asset of $214 million includes $129 million of unamortized incremental deployment costs under the program, $53 million of unamortized costs of the non-AMI meters replaced under the AMI program, and $32 million related to post-test year incremental program deployment costs incurred prior to approval became effective June 2016. Recovery of the post-test year incremental deployment costs will be addressed in a future base rate proceeding.

(d) As of September 30, 2018, ComEd’s regulatory asset of $228 million was comprised of $165 million for the 2016, 2017 and 2018 annual reconciliations and $63 million related to significant one-time events. As of December 31, 2017, ComEd’s regulatory asset of $244 million was comprised of $186 million for the 2016 and 2017 annual reconciliations and $58 million related to significant one-time events.

(e) As of September 30, 2018, ComEd’s regulatory asset of $7 million represents transmission costs recoverable through its FERC approved formula rate. As of September 30, 2018, ComEd’s regulatory liability of $204 million included $101 million related to the PJM Transmission Rate Design Settlement, $72 million related to over-recovered energy costs and $31 million associated with revenues received for renewable energy requirements. As of December 31, 2017, ComEd’s regulatory asset of $6 million represents transmission costs recoverable through its FERC approved formula rate. As of December 31, 2017, ComEd’s regulatory liability of $47 million included $14 million related to over-recovered energy costs and $33 million associated with revenues received for renewable energy requirements.

(f) As of September 30, 2018, PECO’s regulatory asset of $50 million represents the under-recovered natural gas costs under the PGC. As of December 31, 2017, PECO’s regulatory asset of $1 million is related to under-recovered costs under the TSC program. As of September 30, 2018, PECO's regulatory liability of $143 million included $85 million related to the PJM Transmission Rate Design Settlement, $43 million related to over-recovered costs under the DSP program, $3 million related to the over-recovered transmission service charges and $12 million related to over-recovered non-bypassable transmission service charges. As of December 31, 2017, PECO's regulatory liability of $60 million included $36 million related to over-recovered costs under the DSP program, $12 million related to over-recovered non-bypassable transmission service charges and $12 million related to the over-recovered natural gas costs under the PGC.

(g) As of September 30, 2018, BGE's regulatory asset of $72 million included $48 million related to the PJM Transmission Rate Design Settlement, $14 million of costs associated with transmission costs recoverable through its FERC approved formula rate, $7 million related to under-recovered electric energy costs and $3 million of abandonment costs to be recovered upon FERC approval. As of September 30, 2018, BGE's regulatory liability of $7 million related to over-recovered natural gas costs. As of December 31, 2017, BGE’s regulatory asset of $23 million included $7 million of costs associated with transmission costs recoverable through its FERC approved formula rate, $5 million related to under-recovered electric energy costs, $3 million of abandonment costs to be recovered upon FERC approval and $8 million of under-recovered natural gas costs.

(h) As of September 30, 2018, Pepco's regulatory asset of $93 million included $74 million related to the PJM Transmission Rate Design Settlement, $7 million of transmission costs recoverable through its FERC approved formula rate and $12 million related to under-recovered electric energy costs. As of December 31, 2017, Pepco's regulatory asset of $11 million included $3 million of transmission costs recoverable through its FERC approved formula rate and $8 million of under-recovered electric energy costs.

(i) As of September 30, 2018, DPL's regulatory asset of $15 million included $14 million of transmission costs recoverable through its FERC approved formula rate and $1 million related to under-recovered electric energy costs. As of September 30, 2018, DPL's regulatory liability of $14 million included $10 million related to the PJM Transmission Rate Design Settlement and $4 million related to over-recovered electric energy and gas fuel costs. As of December 31, 2017, DPL's regulatory asset of $15 million included $8 million of transmission costs recoverable through its FERC approved formula rate and $7 million related to under-recovered electric energy costs. As of December 31, 2017, DPL's regulatory liability of $1 million related to over-recovered electric energy costs.

(j) As of September 30, 2018, ACE's regulatory asset of $14 million included $7 million of transmission costs recoverable through its FERC approved formula rate and $7 million of under-recovered electric energy costs. As of September 30, 2018, ACE's regulatory liability of $4 million included $3 million related to the PJM Transmission Rate Design Settlement and $1 million related to over-recovered electric energy costs. As of December 31, 2017, ACE's regulatory asset of $26 million included $11 million of transmission costs recoverable through its FERC approved formula rate and $15 million of under-recovered electric energy costs. As of December 31, 2017, ACE's regulatory liability of $3 million related to over-recovered electric energy costs.

(k) As of September 30, 2018, Pepco’s regulatory asset of $18 million represents previously incurred PHI integration costs, including $9 million authorized for recovery in Maryland and $9 million expected to be recovered in the District of Columbia service territory. As of December 31, 2017, Pepco’s regulatory asset of $20 million represents previously incurred PHI integration costs, including $11 million authorized for recovery in Maryland and $9 million expected to be recovered in the District of Columbia service territory.

(l) As of September 30, 2018, DPL’s regulatory asset of $12 million represents previously incurred PHI integration costs, including $4 million authorized for recovery in Maryland, $5 million authorized for recovery in Delaware electric rates, $2 million authorized for recovery in Delaware gas rates and $1 million expected to be recovered in electric rates in the Delaware and Maryland service territories. As of September 30, 2018, DPL’s regulatory liability of $3 million represents net synergy savings incurred related to PHI integration costs that are expected to be returned in electric and gas rates in the Delaware service territory. As of December 31, 2017, DPL’s regulatory asset of $10 million represents previously incurred PHI integration costs, including $4 million authorized for recovery in Maryland, $5 million authorized for recovery in Delaware electric rates, and $1 million expected to be recovered in electric and gas rates in the Maryland and Delaware service territories.

(m) As of September 30, 2018 and December 31, 2017, ACE’s regulatory asset of $10 million and $9 million, respectively, represents previously incurred PHI integration costs expected to be recovered in the New Jersey service territory.

(n) Represents the electric and natural gas distribution costs recoverable from customers under BGE’s decoupling mechanism. As of September 30, 2018, BGE had a regulatory asset of less than $1 million related to under-recovered electric revenue decoupling and a regulatory liability of $17 million related to over-recovered natural gas revenue decoupling. As of December 31, 2017, BGE had a regulatory asset of $10 million related to under-recovered electric revenue decoupling and $4 million related to under-recovered natural gas revenue decoupling.

Purchase Of Receivables

The following tables provide information about the purchased receivables of those companies as of September 30, 2018 and December 31, 2017.

As of September 30, 2018	Exelon			ComEd			PECO			BGE			PHI			Pepco			DPL			ACE
Purchased receivables	$	379		$	120		$	91		$	60		$	108		$	69		$	11		$	28
Allowance for uncollectible accounts(a)	(37		)	(19		)	(5		)	(3		)	(10		)	(5		)	(1		)	(4		)
Purchased receivables, net	$	342		$	101		$	86		$	57		$	98		$	64		$	10		$	24

As of December 31, 2017	Exelon			ComEd			PECO			BGE			PHI			Pepco			DPL			ACE
Purchased receivables	$	298		$	87		$	70		$	58		$	83		$	56		$	9		$	18
Allowance for uncollectible accounts(a)	(31		)	(14		)	(5		)	(3		)	(9		)	(5		)	(1		)	(3		)
Purchased receivables, net	$	267		$	73		$	65		$	55		$	74		$	51		$	8		$	15

_________

(a) For ComEd, BGE, Pepco and DPL, reflects the incremental allowance for uncollectible accounts recorded, which is in addition to the purchase discount. For ComEd, the incremental uncollectible accounts expense is recovered through its Purchase of Receivables with Consolidated Billing tariff.