Income Taxes (Tables)

3 Months Ended

Mar. 31, 2019

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Total income tax expense from operations differs from the amount computed by applying the statutory federal income tax rate to income before income tax expense. The following reconciles such differences:



	Three Months Ended March 31
	2019		2018
Federal statutory rate	21.0	%	21.0	%
State tax (net of federal tax effect)	3.7		3.7
Increases (decreases) in tax from:
Wind PTCs	(7.5	)	—
Regulatory differences ^(a)	(3.9	)	(1.5	)
Other tax credits and allowances (net)	(1.2	)	(1.0	)
Other (net)	—		0.4
Effective income tax rate	12.1	%	22.6	%

^(a)

Regulatory differences for income tax purposes primarily include the ARAM, ARAM deferral and AFUDC - Equity. ARAM is a method to flow back excess deferred taxes to customers. ARAM has been deferred when regulatory treatment has not been established. As Xcel Energy received direction from its regulatory commissions regarding the return of excess deferred taxes to customers, the ARAM deferral was reversed. This resulted in a reduction to tax expense with a corresponding reduction to revenue.

Summary of Statute of Limitations Applicable to Open Tax Years [Table Text Block]

Federal Audits — PSCO is a member of the Xcel Energy affiliated group that files a consolidated federal income tax return. Statute of limitations applicable to Xcel Energy’s federal income tax returns expire as follows:



Tax Year(s)		Expiration
2009 - 2013		October 2019
2014 - 2016		September 2020
2017		September 2021

Reconciliation of Unrecognized Tax Benefits

Unrecognized tax benefits - permanent vs temporary:



(Millions of Dollars)	March 31, 2019		Dec. 31, 2018
Unrecognized tax benefit — Permanent tax positions	$	5.7	$	5.4
Unrecognized tax benefit — Temporary tax positions	4.8		4.9
Total unrecognized tax benefit	$	10.5	$	10.3

Tax Benefits Associated with NOL and Tax Credit Carryforwards

Unrecognized tax benefits were reduced by tax benefits associated with NOL and tax credit carryforwards:



(Millions of Dollars)	March 31, 2019			Dec. 31, 2018
NOL and tax credit carryforwards	$	(6.5	)	$	(5.6	)

Interest Payable related to Unrecognized Tax Benefits [Table Text Block]

Interest payable related to unrecognized tax benefits:



(Millions of Dollars)	March 31, 2019			Dec. 31, 2018
Payable for interest related to unrecognized tax benefits at beginning of period	$	(0.7	)	$	(0.3	)
Interest expense related to unrecognized tax benefits	(0.1		)	(0.4		)
Payable for interest related to unrecognized tax benefits at end of period	$	(0.8	)	$	(0.7	)