Regulatory Assets and Liabilities

Regulatory assets and liabilities are created for amounts that regulators may allow to be collected, or may require to be paid back to customers in future electric rates. SPS would be required to recognize the write-off of regulatory assets and liabilities in net income or other comprehensive income if changes in the utility industry no longer allow for the application of regulatory accounting guidance under GAAP.

Components of regulatory assets:



(Millions of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2018				Dec. 31, 2017
Regulatory Assets			Current		Noncurrent		Current		Noncurrent
Pension and retiree medical obligations	9	Various	$	12.6	$	222.1	$	12.7	$	223.0
Excess deferred taxes - TCJA	7	Various	—		55.9		—		44.7
Recoverable deferred taxes on AFUDC recorded in plant		Plant lives	—		27.9		—		23.9
Net AROs ^(a)	1, 10	Plant lives	—		25.7		—		24.2
Losses on reacquired debt		Term of related debt	0.8		21.9		0.8		22.7
Conservation programs ^(b)	1	One to two years	0.7		0.6		2.7		0.7
Other		Various	11.9		12.1		15.3		23.7
Total regulatory assets			$	26.0	$	366.2	$	31.5	$	362.9


^(a)	Includes amounts recorded for future recovery of AROs.


^(b)	Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions.

Components of regulatory liabilities:



(Millions of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2018				Dec. 31, 2017
Regulatory Liabilities			Current		Noncurrent		Current		Noncurrent
Deferred income tax adjustments and TCJA refunds ^(a)	7	Various	$	2.2	$	569.8	$	—	$	568.6
Plant removal costs	1, 10	Plant lives	—		187.7		—		196.9
Revenue subject to refund		One to two years	11.3		8.1		6.8		6.5
Gain from asset sales		Various	—		2.4		—		2.5
Deferred electric energy costs		Less than one year	56.5		—		48.5		—
Contract valuation adjustments ^(b)	1, 8	Less than one year	14.7		—		12.7		—
Other		Various	1.1		12.9		0.8		10.1
Total regulatory liabilities			$	85.8	$	780.9	$	68.8	$	784.6


^(a)	Includes the revaluation of recoverable/regulated plant ADIT and revaluation impact of non-plant ADIT due to the TCJA.


^(b)	Includes the fair value of certain long-term PPAs used to meet energy capacity requirements.

At Dec. 31, 2018 and 2017, approximately $48 million and $64 million, respectively, of SPS’ regulatory assets represented past expenditures not earning a return. Amounts primarily related to formula rates, losses on reacquired debt and certain rate case expenditures.