						2015				2014				2013
				U.S.	Non-U.S.		Total	U.S.	Non-U.S.		Total	U.S.	Non-U.S.		Total
								(millions of dollars)
Income tax expense
	Federal and non-U.S.
		Current		-		7,126	7,126	1,456		14,755	16,211	1,073		22,115	23,188
		Deferred - net		(1,166)		(571)	(1,737)	900		1,398	2,298	(116)		757	641
	U.S. tax on non-U.S. operations			38		-	38	5		-	5	37		-	37
			Total federal and non-U.S.	(1,128)		6,555	5,427	2,361		16,153	18,514	994		22,872	23,866
	State (1)			(12)		-	(12)	(499)		-	(499)	397		-	397
			Total income tax expense	(1,140)		6,555	5,415	1,862		16,153	18,015	1,391		22,872	24,263
Sales-based taxes				6,402		16,276	22,678	6,310		23,032	29,342	5,992		24,597	30,589
All other taxes and duties
	Other taxes and duties			162		27,103	27,265	378		31,908	32,286	955		32,275	33,230
	Included in production and
		manufacturing expenses		1,157		828	1,985	1,454		1,179	2,633	1,318		1,182	2,500
	Included in SG&A expenses			150		390	540	155		441	596	150		516	666
		Total other taxes and duties		1,469		28,321	29,790	1,987		33,528	35,515	2,423		33,973	36,396
			Total	6,731		51,152	57,883	10,159		72,713	82,872	9,806		81,442	91,248

All other taxes and duties include taxes reported in production and manufacturing and selling, general and administrative (SG&A) expenses. The above provisions for deferred income taxes include a net charge of $177 million in 2015 and net credits of $40 million in 2014 and $310 million in 2013 for the effect of changes in tax laws and rates.

			2015	2014	2013
			(millions of dollars)
Income before income taxes
	United States		147	9,080	9,746
	Non-U.S.		21,819	42,550	47,965
		Total	21,966	51,630	57,711
Theoretical tax			7,688	18,071	20,199
Effect of equity method of accounting			(2,675)	(4,663)	(4,874)
Non-U.S. taxes in excess of theoretical U.S. tax			1,415	5,442	10,528
U.S. tax on non-U.S. operations			38	5	37
State taxes, net of federal tax benefit			(8)	(324)	258
Other			(1,043)	(516)	(1,885)
		Total income tax expense	5,415	18,015	24,263

Effective tax rate calculation
Income taxes			5,415	18,015	24,263
ExxonMobil share of equity company income taxes			3,011	5,678	6,061
		Total income taxes	8,426	23,693	30,324
Net income including noncontrolling interests			16,551	33,615	33,448
		Total income before taxes	24,977	57,308	63,772

Effective income tax rate			34%	41%	48%

Deferred income taxes reflect the impact of temporary differences between the amount of assets and liabilities recognized for financial reporting purposes and such amounts recognized for tax purposes.

Deferred tax liabilities/(assets) are comprised of the following at December 31:

Tax effects of temporary differences for:		2015	2014
		(millions of dollars)

Property, plant and equipment		49,409	51,643
Other liabilities		4,613	4,359
	Total deferred tax liabilities	54,022	56,002

Pension and other postretirement benefits		(6,286)	(8,140)
Asset retirement obligations		(6,277)	(6,162)
Tax loss carryforwards		(4,983)	(4,099)
Other assets		(5,592)	(6,446)
	Total deferred tax assets	(23,138)	(24,847)

Asset valuation allowances		1,730	2,570
	Net deferred tax liabilities	32,614	33,725

In 2015, asset valuation allowances of $1,730 million decreased by $840 million and included net provisions of $681 million and effects of foreign currency translation of $159 million.

Deferred income tax (assets) and liabilities are included in the balance sheet as shown below. Deferred income tax (assets) and liabilities are classified as current or long term consistent with the classification of the related temporary difference – separately by tax jurisdiction.

The Corporation had $51 billion of indefinitely reinvested, undistributed earnings from subsidiary companies outside the U.S. that were retained to fund prior and future capital project expenditures. Deferred taxes have not been recorded for potential future tax obligations as these earnings are expected to be indefinitely reinvested for the foreseeable future. As of December 31, 2015, it is not practical to estimate the unrecognized deferred tax liability associated with these earnings given the future availability of foreign tax credits and uncertainties about the timing of potential remittances

Unrecognized Tax Benefits. The Corporation is subject to income taxation in many jurisdictions around the world. Unrecognized tax benefits reflect the difference between positions taken or expected to be taken on income tax returns and the amounts recognized in the financial statements. The following table summarizes the movement in unrecognized tax benefits:

Gross unrecognized tax benefits		2015	2014	2013
		(millions of dollars)

Balance at January 1		8,986	7,838	7,663
	Additions based on current year's tax positions	903	1,454	1,460
	Additions for prior years' tax positions	496	448	464
	Reductions for prior years' tax positions	(190)	(532)	(249)
	Reductions due to lapse of the statute of limitations	(4)	(117)	(588)
	Settlements with tax authorities	(725)	(43)	(849)
	Foreign exchange effects/other	(70)	(62)	(63)
Balance at December 31		9,396	8,986	7,838

The gross unrecognized tax benefit balances shown above are predominantly related to tax positions that would reduce the Corporation’s effective tax rate if the positions are favorably resolved. Unfavorable resolution of these tax positions generally would not increase the effective tax rate. The 2015, 2014 and 2013 changes in unrecognized tax benefits did not have a material effect on the Corporation’s net income.

Resolution of these tax positions through negotiations with the relevant tax authorities or through litigation will take many years to complete. It is difficult to predict the timing of resolution for tax positions since such timing is not entirely within the control of the Corporation. In the United States, the Corporation has various U.S. federal income tax positions at issue with the Internal Revenue Service for tax years 2006-2011. Unfavorable resolution of these issues would not have a materially adverse effect on the Corporation’s net income or liquidity. The Internal Revenue Service has not completed its audit of tax years after 2011.

It is reasonably possible that the total amount of unrecognized tax benefits could increase by up to 20 percent in the next 12 months, with no material impact on the Corporation’s net income.

The following table summarizes the tax years that remain subject to examination by major tax jurisdiction:

The Corporation classifies interest on income tax-related balances as interest expense or interest income and classifies tax-related penalties as operating expense.

The Corporation incurred $39 million and $42 million in interest expense on income tax reserves in 2015 and 2014, respectively. For 2013, the Corporation’s net interest expense was a credit of $207 million, reflecting the effect of credits from the favorable resolution of prior year tax positions. The related interest payable balances were $223 million and $205 million at December 31, 2015, and 2014, respectively.