
	Year Ended December 31
Millions of dollars	2020		2019		2018
Current income taxes:
Federal	$	1	$	32	$	19
Foreign	(167)		(426)		(428)
State	—		(9)		(15)
Total current	(166)		(403)		(424)
Deferred income taxes:
Federal	372		383		286
Foreign	2		(36)		9
State	70		49		(28)
Total deferred	444		396		267
Income tax (provision) benefit	$	278	$	(7)	$	(157)


	Year Ended December 31
Millions of dollars	2020		2019		2018
United States	$	(3,031)	$	(1,517)	$	1,097
Foreign	(189)		395		717
Total	$	(3,220)	$	(1,122)	$	1,814

Reconciliations between the actual (provision) benefit for income taxes on continuing operations and that computed by applying the United States statutory rate to income (loss) from continuing operations before income taxes were as follows:


	Year Ended December 31
	2020		2019		2018
United States statutory rate	21.0	%	21.0	%	21.0	%
Impact of impairments and other charges	(12.3)		(20.9)		—
Impact of foreign income taxed at different rates	(1.1)		0.8		(3.0)
Valuation allowance against tax assets	0.9		(10.7)		(16.2)
Adjustments of prior year taxes	0.7		13.0		2.0
State income taxes	—		(1.3)		1.9
Venezuela adjustment	—		—		5.7
Impact of U.S. tax reform	—		—		(2.6)



Other items, net	(0.6)		(2.5)		(0.1)
Total effective tax rate on continuing operations	8.6	%	(0.6)	%	8.7	%

During the year ended December 31, 2020, we recorded a total income tax benefit of $278 million on a pre-tax loss of $3.2 billion, resulting in an effective tax rate of 8.6%. The effective tax rate for 2020 was primarily impacted by our geographic mix of earnings, tax adjustments related to the reassessment of prior year tax accruals and valuation allowances on some of our deferred tax assets. The increase in our valuation allowances results from our decreased forecasted ability to generate sufficient taxable income before the expiration of foreign tax credits and net operating losses as a direct result of deteriorated market conditions that led to impairment charges of $3.8 billion in 2020 and $2.5 billion in 2019. See Note 2 for further information.


	December 31
Millions of dollars	2020		2019
Gross deferred tax assets:
Net operating loss carryforwards	$	1,691	$	1,301
Foreign tax credit carryforwards	945		877
Research and development tax credit carryforwards	196		198
Employee compensation and benefits	237		215
Accrued liabilities	263		316
Other	469		382
Total gross deferred tax assets	3,801		3,289
Gross deferred tax liabilities:
Depreciation and amortization	7		373
Operating lease right-of-use assets	86		109

Other	155		58
Total gross deferred tax liabilities	248		540
Valuation allowances	1,394		1,082
Net deferred income tax asset	$	2,159	$	1,667

At December 31, 2020, we had $1.8 billion of domestic and foreign tax-effected net operating loss carryforwards, with approximately $133 million estimated to be utilized against our unrecognized tax benefits. The ultimate realization of these

deferred tax assets depends on our ability to generate sufficient taxable income in the appropriate taxing jurisdiction. Our deferred tax assets from net operating losses, foreign tax credits, and research and development credits will expire as follows:


Millions of dollars	U.S. Net Operating Loss		Foreign Net Operating Loss		Foreign Tax Credits		Research and Development Credit		Total
2021-2025	$	2	$	186	$	533	$	—	$	721
2026-2030	7		125		557		—		689
2031-2041	665		92		—		196		953
Non-Expiring	312		435		—		—		747
	$	986	$	838	$	1,090	$	196	$	3,110

During the year ended December 31, 2020, we increased our valuation allowance on deferred tax assets by $312 million related to $16 million associated with foreign deferred tax assets and $296 million associated with foreign tax credits.

In accordance with the Tax Cuts and Jobs Act of 2017, a company’s foreign earnings accumulated under the legacy tax laws are deemed to be repatriated into the United States. We have provided federal and state income tax related to this deemed repatriation. We have not provided incremental United States income taxes and foreign withholding taxes on undistributed earnings of foreign subsidiaries as of December 31, 2020. The Company generally does not provide for taxes related to its undistributed earnings because such earnings either would not be taxable when remitted or they are considered to be indefinitely reinvested.


Millions of dollars	Unrecognized Tax Benefits			Interest and Penalties
Balance at January 1, 2018	$	333		$	60
Change in prior year tax positions	32			11
Change in current year tax positions	63			—
Cash settlements with taxing authorities	(7)			(2)
Lapse of statute of limitations	(4)			(2)
Balance at December 31, 2018	$	417		$	67
Change in prior year tax positions	25			11
Change in current year tax positions	29			—
Cash settlements with taxing authorities	(4)			—
Lapse of statute of limitations	(42)			(8)
Balance at December 31, 2019	$	425	(a)	$	70
Change in prior year tax positions	(66)			6
Change in current year tax positions	16			—
Cash settlements with taxing authorities	(3)			—
Lapse of statute of limitations	(17)			(5)
Balance at December 31, 2020	$	355	(a)(b)	$	71

(a) Includes $18 million as of December 31, 2020 and $25 million as of December 31, 2019 in foreign unrecognized tax benefits that would give rise to a United States tax credit. As of December 31, 2020 and December 31, 2019, a net $224 million and $271 million without a net operating loss carryforward offset, respectively, of unrecognized tax benefits would positively impact the effective tax rate and be recognized as additional tax benefits in our statement of operations if resolved in our favor.

Our tax returns are subject to review by the taxing authorities in the jurisdictions where we file tax returns. In most cases we are no longer subject to examination by tax authorities for years before 2009. The only significant operating jurisdiction that has tax filings under review or subject to examination by the tax authorities is the United States. The United States federal income tax filings for tax years 2016 through 2019 are currently under review or remain open for review by the U.S. Internal Revenue Service.