Exhibit 99.1

Adjusted Earnings (Non-GAAP) Financial Information

Adjusted Earnings represents income from continuing operations, excluding the effects of the following items from the Company’s GAAP financial results, including the related income tax effects:

Amortization of acquisition-related intangibles - Amortization expense of acquired intangible assets purchased in connection with acquisitions by the Company.

Acquisition expenses and related adjustments - Transaction and integration expenses that are directly related to acquisitions by the Company. Examples include transaction closing costs, professional service fees, restructuring or severance charges, retention payments, employee relocation expenses, facility or other exit-related expenses, recoveries of acquisition-related expenses or post-closing expenses, bridge loan fees, and gains or losses on business combinations.

Litigation reserve adjustments - Adjustments to the Company’s reserves, including accrued interest, for estimated probable losses for its Average Wholesale Price and Securities Litigation matters, as such terms were defined in the Company’s Annual Reports on Form 10-K for the fiscal years ended March 31, 2014 and 2009.

LIFO-related adjustments - Last-In-First-Out (“LIFO”) inventory related adjustments.

Income taxes on Adjusted Earnings are calculated in accordance with Accounting Standards Codification 740, “Income Taxes,” which is the same accounting principle used by the Company when presenting its GAAP financial results.

The Company believes the presentation of non-GAAP measures such as Adjusted Earnings provides useful supplemental information to investors with regard to its core operating performance, as well as assists with the comparison of its past financial performance to the Company’s future financial results. Moreover, the Company believes that the presentation of Adjusted Earnings assists investors’ ability to compare its financial results to those of other companies in the same industry. However, the Company’s Adjusted Earnings measure may be defined and calculated differently by other companies in the same industry.

The Company internally uses non-GAAP financial measures such as Adjusted Earnings in connection with its own financial planning and reporting processes. Specifically, Adjusted Earnings serves as one of the measures management utilizes when allocating resources, deploying capital and assessing business performance and employee incentive compensation. Nonetheless, non-GAAP financial results and related measures disclosed by the Company should not be considered a substitute for, nor superior to, financial results and measures as determined or calculated in accordance with GAAP.

The Company is providing investors the following updated Presentation of Adjusted Earnings (Non-GAAP) as posted to the Company’s website on November 10, 2014:

Exhibit I: provides a reconciliation of Adjusted Earnings per share (Non-GAAP) recast to reflect the reclassifications of the workforce business within our International Technology business from discontinue operations to continue operations, for the fiscal years ended March 31, 2008 through March 31, 2013;

Exhibit II: provides a reconciliation of certain line items from the Company’s GAAP Condensed Consolidated Statements of Operations to Adjusted Earnings (Non-GAAP) for the fiscal years ended March 31, 2008 through March 31, 2013; and,

Exhibit III: provides a reconciliation of the Company’s GAAP segment financial results to Adjusted Earnings (Non-GAAP) for the fiscal years ended March 31, 2008 through March 31, 2013.

Exhibit I

McKESSON CORPORATION

RECONCILIATION OF RECAST ADJUSTED EARNINGS PER SHARE (ADJUSTED EPS, NON-GAAP)

FOR FISCAL 2008 - 2013

(unaudited)

The following are Fiscal 2008 - 2013 Adjusted Earnings Per Share (Non-GAAP), recast to reflect the reclassifications of the workforce business within our International Technology business from discontinued operations to continuing operations:

	Years Ended
	March 31, 2008		March 31, 2009		March 31, 2010		March 31, 2011		March 31, 2012		March 31, 2013
Adjusted EPS, as previously reported	$	3.41	$	4.23	$	4.65	$	5.13	$	6.28	$	6.38
Adjustments due to the reclassifications of the workforce business from discontinued operations to continuing operations		0.04		0.04		0.05		0.06		0.07		0.07
Adjusted EPS, as recast	$	3.45	$	4.27	$	4.70	$	5.19	$	6.35	$	6.45

Certain computations may reflect rounding adjustments.

Exhibit II

Page 1 of 3

McKESSON CORPORATION

RECONCILIATION OF GAAP OPERATING RESULTS TO ADJUSTED EARNINGS (NON-GAAP)

FOR FISCAL 2008 - 2013

(unaudited)

(in millions, except per share amounts)

The following are Fiscal 2008 - 2013 Adjusted Earnings (Non-GAAP), recast to reflect the reclassifications of the workforce business within our International Technology business from discontinued operations to continuing operations:

	Year Ended March 31, 2013
	As Reported (GAAP)			Amortization of Acquisition- Related Intangibles			Acquisition Expenses and Related Adjustments			Litigation Reserve Adjustments			LIFO-Related Adjustments			Adjusted Earnings (Non- GAAP)
Revenues	$	122,196		$	—		$	—		$	—		$	—		$	122,196
Gross profit	$	6,881		$	13		$	—		$	—		$	13		$	6,907
Operating expenses		(4,534	)		196			(10	)		72			—			(4,276	)
Other income, net		34			—			—			—			—			34
Impairment of equity investment		(191	)		—			—			—			—			(191	)
Interest expense		(240	)		—			11			—			—			(229	)
Income from continuing operations before income taxes		1,950			209			1			72			13			2,245
Income tax expense		(587	)		(76	)		(6	)		(27	)		(5	)		(701	)
Income from continuing operations after tax		1,363			133			(5	)		45			8			1,544
Income from continuing operations, net of tax, attributable to noncontrolling interests		—			—			—			—			—			—
Income from continuing operations, net of tax, attributable to McKesson Corporation	$	1,363		$	133		$	(5	)	$	45		$	8		$	1,544
Diluted earnings per common share from continuing operations, net of tax, attributable to McKesson Corporation (a)	$	5.69		$	0.56		$	(0.02	)	$	0.19		$	0.03		$	6.45
Diluted weighted average common shares		239			239			239			239			239			239
	Year Ended March 31, 2012
	As Reported (GAAP)			Amortization of Acquisition- Related Intangibles			Acquisition Expenses and Related Adjustments			Litigation Reserve Adjustments			LIFO-Related Adjustments			Adjusted Earnings (Non- GAAP)
Revenues	$	122,453		$	—		$	—		$	—		$	—		$	122,453
Gross profit	$	6,435		$	17		$	—		$	—		$	11		$	6,463
Operating expenses		(4,289	)		167			26			149			—			(3,947	)
Other income, net		20			—			—			—			—			20
Impairment of equity investment		—			—			—			—			—			—
Interest expense		(251	)		—			—			—			—			(251	)
Income from continuing operations before income taxes		1,915			184			26			149			11			2,285
Income tax expense		(521	)		(71	)		(10	)		(89	)		(4	)		(695	)
Income from continuing operations after tax		1,394			113			16			60			7			1,590
Income from continuing operations, net of tax, attributable to noncontrolling interests		—			—			—			—			—			—
Income from continuing operations, net of tax, attributable to McKesson Corporation	$	1,394		$	113		$	16		$	60		$	7		$	1,590
Diluted earnings per common share from continuing operations, net of tax, attributable to McKesson Corporation (a)	$	5.56		$	0.45		$	0.07		$	0.24		$	0.03		$	6.35
Diluted weighted average common shares		251			251			251			251			251			251

(a) Certain computations may reflect rounding adjustments.

Exhibit II

Page 2 of 3

	Year Ended March 31, 2011
	As Reported (GAAP)			Amortization of Acquisition- Related Intangibles			Acquisition Expenses and Related Adjustments			Litigation Reserve Adjustments			LIFO- Related Adjustments			Adjusted Earnings (Non-GAAP)
Revenues	$	111,804		$	—		$	—		$	—		$	—		$	111,804
Gross profit	$	5,828		$	16		$	—		$	—		$	3		$	5,847
Operating expenses		(4,041	)		115			43			213			—			(3,670	)
Other income, net		35			—			(16	)		—			—			19
Impairment of equity investment		—			—			—			—			—			—
Interest expense		(222	)		—			25			—			—			(197	)
Income from continuing operations before income taxes		1,600			131			52			213			3			1,999
Income tax expense		(503	)		(51	)		(16	)		(64	)		(1	)		(635	)
Income from continuing operations after tax		1,097			80			36			149			2			1,364
Income from continuing operations, net of tax, attributable to noncontrolling interests		—			—			—			—			—			—
Income from continuing operations, net of tax, attributable to McKesson Corporation	$	1,097		$	80		$	36		$	149		$	2		$	1,364
Diluted earnings per common share from continuing operations, net of tax, attributable to McKesson Corporation (a)	$	4.17		$	0.30		$	0.14		$	0.57		$	0.01		$	5.19
Diluted weighted average common shares		263			263			263			263			263			263
	Year Ended March 31, 2010
	As Reported (GAAP)			Amortization of Acquisition- Related Intangibles			Acquisition Expenses and Related Adjustments			Litigation Reserve Adjustments			LIFO- Related Adjustments			Adjusted Earnings (Non-GAAP)
Revenues	$	108,425		$	—		$	—		$	—		$	—		$	108,425
Gross profit	$	5,527		$	21		$	—		$	—		$	8		$	5,556
Operating expenses		(3,558	)		97			—			(20	)		—			(3,481	)
Other income, net		43			—			—			—			—			43
Impairment of equity investment		—			—			—			—			—			—
Interest expense		(187	)		—			—			—			—			(187	)
Income from continuing operations before income taxes		1,825			118			—			(20	)		8			1,931
Income tax expense		(605	)		(46	)					8			(3	)		(646	)
Income from continuing operations after tax		1,220			72			—			(12	)		5			1,285
Income from continuing operations, net of tax, attributable to noncontrolling interests		—			—			—			—			—			—
Income from continuing operations, net of tax, attributable to McKesson Corporation	$	1,220		$	72		$	—		$	(12	)	$	5		$	1,285
Diluted earnings per common share from continuing operations, net of tax, attributable to McKesson Corporation (a)	$	4.46		$	0.26		$	—		$	(0.04	)	$	0.02		$	4.70
Diluted weighted average common shares		273			273			—			273			273			273

(a) Certain computations may reflect rounding adjustments.

Exhibit II

Page 3 of 3

	Year Ended March 31, 2009
	As Reported (GAAP)			Amortization of Acquisition- Related Intangibles			Acquisition Expenses and Related Adjustments			Litigation Reserve Adjustments			LIFO-Related Adjustments			Adjusted Earnings (Non-GAAP)
Revenues	$	106,376		$	—		$	—		$	—		$	—		$	106,376
Gross profit	$	5,251		$	29		$	—		$	—		$	8		$	5,288
Operating expenses		(4,080	)		97			—			493			—			(3,490	)
Other income, net		74			—			—			—			—			74
Impairment of equity investment		(63	)		—			—			—			—			(63	)
Interest expense		(144	)		—			—			—			—			(144	)
Income from continuing operations before income taxes		1,038			126			—			493			8			1,665
Income tax expense		(240	)		(49	)					(182	)		(3	)		(474	)
Income from continuing operations after tax		798			77			—			311			5			1,191
Income from continuing operations, net of tax, attributable to noncontrolling interests		—			—			—			—			—			—
Income from continuing operations, net of tax, attributable to McKesson Corporation	$	798		$	77		$	—		$	311		$	5		$	1,191
Diluted earnings per common share from continuing operations, net of tax, attributable to McKesson Corporation (a)	$	2.86		$	0.28		$	—		$	1.11		$	0.02		$	4.27
Diluted weighted average common shares		279			279			—			279			279			279
	Year Ended March 31, 2008
	As Reported (GAAP)			Amortization of Acquisition- Related Intangibles			Acquisition Expenses and Related Adjustments			Litigation Reserve Adjustments			LIFO-Related Adjustments			Adjusted Earnings (Non-GAAP)
Revenues	$	101,454		$	—		$	—		$	—		$	—		$	101,454
Gross profit	$	4,888		$	27		$	—		$	—		$	(14	)	$	4,901
Operating expenses		(3,427	)		78			4			(5	)		—			(3,350	)
Other income, net		119			—			—			—			—			119
Impairment of equity investment		—			—			—			—			—			—
Interest expense		(142	)		—			—			—			—			(142	)
Income from continuing operations before income taxes		1,438			105			4			(5	)		(14	)		1,528
Income tax expense		(466	)		(40	)		(2	)		2			5			(501	)
Income from continuing operations after tax		972			65			2			(3	)		(9	)		1,027
Income from continuing operations, net of tax, attributable to noncontrolling interests		—			—			—			—			—			—
Income from continuing operations, net of tax, attributable to McKesson Corporation	$	972		$	65		$	2		$	(3	)	$	(9	)	$	1,027
Diluted earnings per common share from continuing operations, net of tax, attributable to McKesson Corporation (a)	$	3.26		$	0.22		$	0.01		$	(0.01	)	$	(0.03	)	$	3.45
Diluted weighted average common shares		298			298			298			298			298			298

(a) Certain computations may reflect rounding adjustments.

Exhibit III

Page 1 of 2

McKESSON CORPORATION

RECONCILIATION OF GAAP SEGMENT FINANCIAL RESULTS TO ADJUSTED EARNINGS (NON-GAAP)

FOR FISCAL 2008 - 2013

(unaudited)

(in millions)

The following are Fiscal 2008 - 2013 Adjusted Earnings (Non-GAAP), recast to reflect the reclassifications of the workforce business within our International Technology business from discontinued operations to continuing operations:

	Year Ended March 31, 2013												Year Ended March 31, 2012												Year Ended March 31, 2011
	Distribution Solutions			Technology Solutions			Corporate & Interest Expense			Total			Distribution Solutions			Technology Solutions			Corporate & Interest Expense			Total			Distribution Solutions			Technology Solutions			Corporate & Interest Expense			Total
As Reported (GAAP):
Revenues	$	119,046		$	3,150		$	—		$	122,196		$	119,424		$	3,029		$	—		$	122,453		$	108,889		$	2,915		$	—		$	111,804
Gross profit	$	5,435		$	1,446		$	—		$	6,881		$	5,057		$	1,378		$	—		$	6,435		$	4,565		$	1,263		$	—		$	5,828
Operating expenses		(3,068	)		(1,120	)		(346	)		(4,534	)		(2,854	)		(1,022	)		(413	)		(4,289	)		(2,673	)		(1,000	)		(368	)		(4,041	)
Other income, net		19			4			11			34			16			4			—			20			5			3			27			35
Impairment of equity investment		(191	)		—			—			(191	)		—			—			—			—			—			—			—			—
Income from continuing operations before interest expense and income taxes		2,195			330			(335	)		2,190			2,219			360			(413	)		2,166			1,897			266			(341	)		1,822
Interest expense		—			—			(240	)		(240	)		—			—			(251	)		(251	)		(1	)		—			(221	)		(222	)
Income from continuing operations before income taxes	$	2,195		$	330		$	(575	)	$	1,950		$	2,219		$	360		$	(664	)	$	1,915		$	1,896		$	266		$	(562	)	$	1,600
Gross profit margin		4.57	%		45.90	%		—			5.63	%		4.23	%		45.49	%		—			5.26	%		4.19	%		43.33	%		—			5.21	%
Operating expenses as a % of revenues		2.58	%		35.56	%		—			3.71	%		2.39	%		33.74	%		—			3.50	%		2.45	%		34.31	%		—			3.61	%
Operating pre-tax profit as a % of revenues		1.84	%		10.48	%		—			1.79	%		1.86	%		11.89	%		—			1.77	%		1.74	%		9.13	%		—			1.63	%
Pre-Tax Adjustments:
Gross profit	$	2		$	11		$	—		$	13		$	1		$	16		$	—		$	17		$	—		$	16		$	—		$	16
Operating expenses		146			49			1			196			120			47			—			167			70			45			—			115
Amortization of acquisition-related intangibles		148			60			1			209			121			63			—			184			70			61			—			131
Gross profit		—			—			—			—			—			—			—			—			—			—			—			—
Operating expenses		47			7			(64	)		(10	)		24			1			1			26			41			—			2			43
Other income, net		—			—			—			—			—			—			—			—			—			—			(16	)		(16	)
Interest expense		—			—			11			11			—			—			—			—			—			—			25			25
Acquisition expenses and related adjustments		47			7			(53	)		1			24			1			1			26			41			—			11			52
Operating expenses - Litigation reserve adjustments		72			—			—			72			149			—			—			149			213			—			—			213
Gross profit - LIFO-related adjustments		13			—			—			13			11			—			—			11			3			—			—			3
Total pre-tax adjustments	$	280		$	67		$	(52	)	$	295		$	305		$	64		$	1		$	370		$	327		$	61		$	11		$	399
Adjusted Earnings (Non-GAAP):
Revenues	$	119,046		$	3,150		$	—		$	122,196		$	119,424		$	3,029		$	—		$	122,453		$	108,889		$	2,915		$	—		$	111,804
Gross profit	$	5,450		$	1,457		$	—		$	6,907		$	5,069		$	1,394		$	—		$	6,463		$	4,568		$	1,279		$	—		$	5,847
Operating expenses		(2,803	)		(1,064	)		(409	)		(4,276	)		(2,561	)		(974	)		(412	)		(3,947	)		(2,349	)		(955	)		(366	)		(3,670	)
Other income, net		19			4			11			34			16			4			—			20			5			3			11			19
Impairment of equity investment		(191	)		—			—			(191	)		—			—			—			—			—			—			—			—
Income from continuing operations before interest expense and income taxes		2,475			397			(398	)		2,474			2,524			424			(412	)		2,536			2,224			327			(355	)		2,196
Interest expense		—			—			(229	)		(229	)		—			—			(251	)		(251	)		(1	)		—			(196	)		(197	)
Income from continuing operations before income taxes	$	2,475		$	397		$	(627	)	$	2,245		$	2,524		$	424		$	(663	)	$	2,285		$	2,223		$	327		$	(551	)	$	1,999
Gross profit margin		4.58	%		46.25	%		—			5.65	%		4.24	%		46.02	%		—			5.28	%		4.20	%		43.88	%		—			5.23	%
Operating expenses as a % of revenues		2.35	%		33.78	%		—			3.50	%		2.14	%		32.16	%		—			3.22	%		2.16	%		32.76	%		—			3.28	%
Operating pre-tax profit as a % of revenues		2.08	%		12.60	%		—			2.02	%		2.11	%		14.00	%		—			2.07	%		2.04	%		11.22	%		—			1.96	%

Exhibit III

Page 2 of 2

	Year Ended March 31, 2010												Year Ended March 31, 2009												Year Ended March 31, 2008
	Distribution Solutions			Technology Solutions			Corporate & Interest Expense			Total			Distribution Solutions			Technology Solutions			Corporate & Interest Expense			Total			Distribution Solutions			Technology Solutions			Corporate & Interest Expense			Total
As Reported (GAAP):
Revenues	$	105,578		$	2,847		$	—		$	108,425		$	103,568		$	2,808		$	—		$	106,376		$	98,719		$	2,735		$	—		$	101,454
Gross profit	$	4,219		$	1,308		$	—		$	5,527		$	3,955		$	1,296		$	—		$	5,251		$	3,586		$	1,302		$	—		$	4,888
Operating expenses		(2,260	)		(967	)		(331	)		(3,558	)		(2,777	)		(994	)		(309	)		(4,080	)		(2,138	)		(1,011	)		(278	)		(3,427	)
Other income (expense), net		29			5			9			43			43			6			25			74			35			9			75			119
Impairment of equity investment		—			—			—			—			(63	)		—			—			(63	)		—			—			—			—
Income from continuing operations before interest expense and income taxes		1,988			346			(322	)		2,012			1,158			308			(284	)		1,182			1,483			300			(203	)		1,580
Interest expense		(2	)		(2	)		(183	)		(187	)		2			(4	)		(142	)		(144	)		4			(4	)		(142	)		(142	)
Income from continuing operations before income taxes	$	1,986		$	344		$	(505	)	$	1,825		$	1,160		$	304		$	(426	)	$	1,038		$	1,487		$	296		$	(345	)	$	1,438
Gross profit margin		4.00	%		45.94	%		—			5.10	%		3.82	%		46.15	%		—			4.94	%		3.63	%		47.61	%		—			4.82	%
Operating expenses as a % of revenues		2.14	%		33.97	%		—			3.28	%		2.68	%		35.40	%		—			3.84	%		2.17	%		36.97	%		—			3.38	%
Operating pre-tax profit as a % of revenues		1.88	%		12.15	%		—			1.86	%		1.12	%		10.97	%		—			1.11	%		1.50	%		10.97	%		—			1.56	%
Pre-Tax Adjustments:
Gross profit	$	1		$	20		$	—		$	21		$	1		$	28		$	—		$	29		$	1		$	26		$	—		$	27
Operating expenses		50			47			—			97			50			47			—			97			28			50			—			78
Amortization of acquisition-related intangibles		51			67			—			118			51			75			—			126			29			76			—			105
Gross profit		—			—			—			—			—			—			—			—			—			—			—			—
Operating expenses		—			—			—			—			—			—			—			—			4			—			—			4
Other income, net		—			—			—			—			—			—			—			—			—			—			—			—
Interest expense		—			—			—			—			—			—			—			—			—			—			—			—
Acquisition expenses and related adjustments		—			—			—			—			—			—			—			—			4			—			—			4
Operating expenses - Litigation reserve adjustments		—			—			(20	)		(20	)		493			—			—			493			—			—			(5	)		(5	)
Gross profit - LIFO-related adjustments		8			—			—			8			8			—			—			8			(14	)		—			—			(14	)
Total pre-tax adjustments	$	59		$	67		$	(20	)	$	106		$	552		$	75		$	—		$	627		$	19		$	76		$	(5	)	$	90
Adjusted Earnings (Non-GAAP):
Revenues	$	105,578		$	2,847		$	—		$	108,425		$	103,568		$	2,808		$	—		$	106,376		$	98,719		$	2,735		$	—		$	101,454
Gross profit	$	4,228		$	1,328		$	—		$	5,556		$	3,964		$	1,324		$	—		$	5,288		$	3,573		$	1,328		$	—		$	4,901
Operating expenses		(2,210	)		(920	)		(351	)		(3,481	)		(2,234	)		(947	)		(309	)		(3,490	)		(2,106	)		(961	)		(283	)		(3,350	)
Other income, net		29			5			9			43			43			6			25			74			35			9			75			119
Impairment of equity investment		—			—			—			—			(63	)		—			—			(63	)		—			—			—			—
Income from continuing operations before interest expense and income taxes		2,047			413			(342	)		2,118			1,710			383			(284	)		1,809			1,502			376			(208	)		1,670
Interest expense		(2	)		(2	)		(183	)		(187	)		2			(4	)		(142	)		(144	)		4			(4	)		(142	)		(142	)
Income from continuing operations before income taxes	$	2,045		$	411		$	(525	)	$	1,931		$	1,712		$	379		$	(426	)	$	1,665		$	1,506		$	372		$	(350	)	$	1,528
Gross profit margin		4.00	%		46.65	%		—			5.12	%		3.83	%		47.15	%		—			4.97	%		3.62	%		48.56	%		—			4.83	%
Operating expenses as a % of revenues		2.09	%		32.31	%		—			3.21	%		2.16	%		33.73	%		—			3.28	%		2.13	%		35.14	%		—			3.30	%
Operating pre-tax profit as a % of revenues		1.94	%		14.51	%		—			1.95	%		1.65	%		13.64	%		—			1.70	%		1.52	%		13.75	%		—			1.65	%