Significant Accounting Policies	12 Months Ended
Mar. 31, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Nature of Operations: McKesson Corporation (“McKesson,” the “Company,” the “Registrant” or “we” and other similar pronouns) delivers a comprehensive offering of pharmaceuticals and medical supplies and provides services to help our customers improve the efficiency and effectiveness of their healthcare operations. Commencing in the first quarter of 2019, our new segment reporting structure was implemented and we have reported our financial results in three reportable segments on a retrospective basis: U.S. Pharmaceutical and Specialty Solutions, European Pharmaceutical Solutions and Medical-Surgical Solutions. All remaining operating segments and business activities that are not significant enough to require separate reportable segment disclosure are included in Other. Refer to Financial Note 28, “Segments of Business” for more information. Basis of Presentation: The consolidated financial statements and accompanying notes are prepared in accordance with U. S. generally accepted accounting principles (“GAAP”). The consolidated financial statements of McKesson include the financial statements of all wholly-owned subsidiaries and majority-owned or controlled companies. For those consolidated subsidiaries where our ownership is less than 100%, the portion of the net income or loss allocable to the noncontrolling interests is reported as “Net Income Attributable to Noncontrolling Interests” on the consolidated statements of operations. All significant intercompany balances and transactions have been eliminated in consolidation including the intercompany portion of transactions with equity method investees. We consider ourselves to control an entity if we are the majority owner of or have voting control over such entity. We also assess control through means other than voting rights (“variable interest entities” or “VIEs”) and determine which business entity is the primary beneficiary of the VIE. We consolidate VIEs when it is determined that we are the primary beneficiary of the VIE. Investments in business entities in which we do not have control but have the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method. Refer to Financial Note 5, “Healthcare Technology Net Asset Exchange” for further information on our equity method investment in Change Healthcare, LLC (“Change Healthcare”). Fiscal Period: The Company’s fiscal year begins on April 1 and ends on March 31. Unless otherwise noted, all references to a particular year shall mean the Company’s fiscal year. Reclassifications: Certain prior year amounts have been reclassified to conform to the current year presentation. Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires that we make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimated amounts. Cash and Cash Equivalents: All highly liquid debt and money market instruments purchased with original maturity of three months or less at the date of acquisition are included in cash and cash equivalents. Cash equivalents are carried at fair value. Cash equivalents are primarily invested in AAA rated prime and U.S. government money market funds denominated in U.S. dollars, overnight repurchase agreements collateralized by U.S. government securities, Canadian government securities and/or securities that are guaranteed or sponsored by the U.S. government and an AAA rated prime money market fund denominated in British pound sterling. The remaining cash and cash equivalents are deposited with several financial institutions. Deposits may exceed the amounts insured by the Federal Deposit Insurance Corporation in the U.S. and similar deposit insurance programs in other jurisdictions. We mitigate the risk of our short-term investment portfolio by depositing funds with reputable financial institutions and monitoring risk profiles and investment strategies of money market funds. Restricted Cash: Cash that is subject to legal restrictions or is unavailable for general operating purposes is classified as restricted cash and is included within “Prepaid expenses and other” and “Other Noncurrent Assets” in the consolidated balance sheets. At March 31, 2019 and 2018, our restricted cash balance was not material. Marketable Securities Available-for-Sale: Our marketable securities, which are available-for-sale, are carried at fair value and are included within “Prepaid expenses and other” in the consolidated balance sheets. The unrealized gains and losses, net of the related tax effect, computed in marking these securities to market have been reported within stockholders’ equity. At March 31, 2019 and 2018, marketable securities were not material. In determining whether an other-than-temporary decline in market value has occurred, we consider the duration that, and extent to which, the fair value of the investment is below its cost, the financial condition and future prospects of the issuer or underlying collateral of a security, and our intent and ability to retain the security in order to allow for an anticipated recovery in fair value. Other-than-temporary declines in fair value from amortized cost for available-for-sale equity securities that we intend to sell or would more likely than not be required to sell before the expected recovery of the amortized cost basis are charged to other income, net, in the period in which the loss occurs. Equity Method Investments: Investments in business entities in which we do not have control, but have the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method. We evaluate our equity method investments for impairment whenever an event or change in circumstances occurs that may have a significant adverse impact on the carrying value of the investment. If a loss in value has occurred that is deemed to be other-than-temporary, an impairment loss is recorded. Refer to Financial Note 5, “Healthcare Technology Net Asset Exchange” for further information relating to our equity method investment in Change Healthcare, LLC (“Change Healthcare”). Concentrations of Credit Risk and Receivables: Our trade accounts receivable are subject to concentrations of credit risk with customers primarily in our U.S. Pharmaceutical and Specialty Solutions segment. During 2019, sales to our ten largest customers, including group purchasing organizations (“GPOs”) accounted for approximately 49.9% of our total consolidated revenues. Sales to our largest customer, CVS Health (“CVS”), accounted for approximately 19.4% of our total consolidated revenues. At March 31, 2019, trade accounts receivable from our ten largest customers were approximately 31.9% of total trade accounts receivable. Accounts receivable from CVS were approximately 18.4% of total trade accounts receivable. As a result, our sales and credit concentration is significant. We also have agreements with GPOs, each of which functions as a purchasing agent on behalf of member hospitals, pharmacies and other healthcare providers, as well as with government entities and agencies. The accounts receivables balances are with individual members of the GPOs, and therefore no significant concentration of credit risk exists. A material default in payment, a material reduction in purchases from these or any other large customers, or the loss of a large customer or customer groups could have a material adverse impact on our financial condition, results of operations and liquidity. In addition, trade receivables are subject to concentrations of credit risk with customers in the institutional, retail and healthcare provider sectors, which can be affected by a downturn in the economy and changes in reimbursement policies. This credit risk is mitigated by the size and diversity of the customer base as well as its geographic dispersion. We estimate the receivables for which we do not expect full collection based on historical collection rates and ongoing evaluations of the creditworthiness of our customers. An allowance is recorded in our consolidated financial statements for these estimated amounts. Financing Receivables: We assess and monitor credit risk associated with financing receivables, primarily notes receivables, through regular review of our collection experience in determining our allowance for loan losses. On an ongoing basis, we also evaluate credit quality of our financing receivables utilizing aging of receivables and write-offs, as well as considering existing economic conditions, to determine if an allowance is required. Financing receivables are derecognized if legal title to them has been transferred and all related risks and rewards incidental to ownership have passed to the buyer. As of March 31, 2019 and 2018, financing receivables and the related allowance were not material to our consolidated financial statements. Inventories: Inventories consist of merchandise held for resale. Prior to 2018, we reported inventories at the lower of cost or market (“LCM”). Effective in the first quarter of 2018, we report inventories at the lower of cost or net realizable value, except for inventories determined using the last-in, first-out (“LIFO”) method. The majority of the cost of domestic inventories is determined using the LIFO method. The majority of the cost of inventories held in foreign locations is based on first-in, first-out method and weighted average purchase prices. Rebates, cash discounts, and other incentives received from vendors are recognized within cost of sales upon the sale of the related inventory. The LIFO method was used to value approximately 62% and 63% of our inventories at March 31, 2019 and 2018. If we had used the moving average method of inventory valuation, inventories would have been approximately $696 million and $906 million higher than the amounts reported at March 31, 2019 and 2018. These amounts are equivalent to our LIFO reserves. Our LIFO valuation amount includes both pharmaceutical and non-pharmaceutical products. We recognized LIFO credits of $210 million, $99 million and $7 million in 2019, 2018 and 2017 in cost of sales within our consolidated statements of operations. A LIFO charge is recognized when the net effect of price increases on pharmaceutical and non-pharmaceutical products held in inventory exceeds the impact of price declines, including the effect of branded pharmaceutical products that have lost market exclusivity. A LIFO credit is recognized when the net effect of price declines exceeds the impact of price increases on pharmaceutical and non-pharmaceutical products held in inventory. We believe that moving average inventory costing method provides a reasonable estimation of the current cost of replacing inventory (i.e., “market”). As such, our LIFO inventory is valued at the lower of LIFO cost or market. As of March 31, 2019 and 2018, inventories at LIFO did not exceed market. Shipping and Handling Costs: We include costs to pack and deliver inventory to our customers in selling, distribution and administrative expenses. Shipping and handling costs of $951 million, $914 million, and $814 million were recognized in 2019, 2018 and 2017. Property, Plant and Equipment: We state our property, plant and equipment (“PPE”) at cost and depreciate them under the straight-line method at rates designed to distribute the cost of PPE over estimated service lives ranging from one to thirty years. When certain events or changes in operating conditions occur, an impairment assessment may be performed on the recoverability of the carrying amounts. Goodwill: Goodwill is tested for impairment on an annual basis in the fourth quarter or more frequently if indicators of potential impairment exist. Impairment testing is conducted at the reporting unit level, which is generally defined as an operating segment or one level below an operating segment (also known as a component), for which discrete financial information is available and segment management regularly reviews the operating results of that reporting unit. The goodwill testing requires us to compare the estimated fair value of a reporting unit to its carrying value. If the carrying value of the reporting unit is lower than its estimated fair value, no further evaluation is required. If the carrying value of the reporting unit exceeds its estimated fair value, an impairment charge is recorded for that excess, limited to the total amount of goodwill allocated to that reporting unit. To estimate the fair value of our reporting units, we generally use a combination of the market approach and the income approach. Under the market approach, we estimate fair value by comparing the business to similar businesses or guideline companies whose securities are actively traded in public markets. Under the income approach, we use a discounted cash flow (“DCF”) model in which cash flows anticipated over future periods, plus a terminal value at the end of that time horizon, are discounted to their present value using an estimated expected rate of return. Other estimates inherent in both the market and income approaches include long-term growth rates, projected revenues, earnings and cash flow forecasts for the reporting units. In addition, we compare the aggregate of the reporting units’ fair values to the Company’s market capitalization as a further corroboration of the fair values. Goodwill testing requires a complex series of assumptions and judgments by management in projecting future operating results, selecting guideline companies for comparisons and assessing risks. The use of alternative assumptions and estimates could affect the fair values and change the impairment determinations. Intangible Assets: Currently all of our intangible assets are subject to amortization and are amortized based on the pattern of their economic consumption or on a straight-line basis over their estimated useful lives, ranging from one to 38 years. We review intangible assets for impairment at an asset group level whenever events or changes in circumstances indicate that the carrying value of the assets may not be recoverable. Determination of recoverability is based on the lowest level of identifiable estimated future undiscounted cash flows resulting from use of the asset and its eventual disposition. Measurement of any impairment loss is based on the excess of the carrying value of the asset group over its estimated fair market value. Capitalized Software Held for Internal Use: We capitalize costs of software held for internal use during the application development stage of a project and amortize those costs over their estimated useful lives ranging from one to ten years. As of March 31, 2019 and 2018, capitalized software held for internal use was $394 million and $425 million, net of accumulated amortization of $1,246 million and $1,182 million, and was included in other noncurrent assets in the consolidated balance sheets. Insurance Programs: Under our insurance programs, we seek to obtain coverage for catastrophic exposures as well as those risks required to be insured by law or contract. It is our policy to retain a significant portion of certain losses primarily related to workers’ compensation and comprehensive general, product and vehicle liability. Provisions for losses expected under these programs are recorded based on our estimate of the aggregate liability for claims incurred as well as for claims incurred but not yet reported. Such estimates utilize certain actuarial assumptions followed in the insurance industry. Revenue Recognition: Revenue is recognized when an entity satisfies a performance obligation by transferring control of a promised good or service to a customer in an amount that reflects the consideration to which the entity expects to be entitled for that good or service. Revenues generated from the distribution of pharmaceutical and medical products represent the majority of our revenues. We order product from the manufacturer, receive and carry the product at our central distribution facilities and deliver the product directly to our customers’ warehouses, hospitals or retail pharmacies. The distribution business primarily generates revenue from a contract related to a confirmed purchase order with a customer in a distribution arrangement. Revenue is recognized when control of goods is transferred to the customer which occurs upon our delivery to the customer or upon customer pick-up. We also earn revenues from a variety of other sources including our retail, services and technology businesses. Retail revenues are recognized at the point of sale. Service revenues, including technology service revenues, are recognized when services are rendered. Revenues derived from distribution and retail business at the point of sale, and revenues derived from services represent approximately 98% and 2% of total revenues for the year ended on March 31, 2019. Revenues are recorded gross when we are the principal in the transaction, have the ability to direct the use of the goods or services prior to transfer to a customer, are responsible for fulfilling the promise to our customer, have latitude in establishing prices, and control the relationship with the customer. We record our revenues net of sales taxes. Revenues are measured based on the amount of consideration that we expect to receive, reduced by estimates for return allowances, discounts and rebates using historical data. Sales returns from customers were approximately $2.9 billion in 2019, and $3.1 billion in 2018 and 2017. Assets for the right to recover products from customers and the associated refund liabilities for return allowances were not material as of March 31, 2019. Shipping and handling costs associated with outbound freight after control over a product has transferred to a customer are accounted for as fulfillment costs and are included in selling, distribution and administrative expenses. We record deferred revenues when payments are received or due in advance of our performance. Deferred revenues are primarily from our services arrangements and are recognized as revenues over the periods when services are performed. We had no material contract assets, contract liabilities or deferred contract costs recorded on the consolidated balance sheets. We elected the practical expedient and generally expense costs to obtain a contract when incurred because the amortization period would have been one year or less. Supplier Incentives: Fees for services and other incentives received from suppliers, relating to the purchase or distribution of inventory, are considered product discounts and are generally reported as a reduction to cost of sales. Supplier Reserves: We establish reserves against amounts due from suppliers relating to various fees for services and price and rebate incentives, including deductions taken against payments otherwise due to them. These reserve estimates are established based on judgment after considering the status of current outstanding claims, historical experience with the suppliers, the specific incentive programs and any other pertinent information available. We evaluate the amounts due from suppliers on a continual basis and adjust the reserve estimates when appropriate based on changes in facts and circumstances. Adjustments to supplier reserves are generally included within cost of sales. The ultimate outcome of any outstanding claims may be different than our estimate. The supplier reserves primarily pertain to our U.S. Pharmaceutical and Specialty Solutions segment. Income Taxes: We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or the tax returns. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statements and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. The amount recognized is measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon effective settlement. Deferred taxes are not provided on undistributed earnings of our foreign operations that are considered to be permanently reinvested. Foreign Currency Translation: The reporting currency of the Company and its subsidiaries is the U.S. dollar. Our foreign subsidiaries generally consider their local currency to be their functional currency. Foreign currency-denominated assets and liabilities of these foreign subsidiaries are translated into U.S. dollars at period-end exchange rates, while revenues and expenses are translated at average exchange rates during the corresponding period and stockholders’ equity accounts are primarily translated at historical exchange rates. Foreign currency translation adjustments are included in other comprehensive income or loss in the consolidated statements of comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. Realized gains and losses from currency exchange transactions are recorded in operating expenses in the consolidated statements of operations and were not material to our consolidated results of operations in 2019, 2018 or 2017. We release cumulative translation adjustments from stockholders’ equity into earnings as a gain or loss only upon complete or substantially complete liquidation of a controlling interest in a subsidiary or a group of assets within a foreign entity. We also release all or a pro rata portion of the cumulative translation adjustments into earnings upon the sale of an equity method investment that is a foreign entity. Derivative Financial Instruments: Derivative financial instruments are used principally in the management of foreign currency exchange and interest rate exposures and are recorded on the consolidated balance sheets at fair value. If a derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. We use foreign currency-denominated notes and cross-currency swaps to hedge a portion of our net investment in our foreign subsidiaries. We use cash flow hedges primarily to reduce the effects of foreign currency exchange rate risk related to intercompany loans denominated in non-functional currencies. If the financial instrument is designated as a cash flow hedge or net investment hedge, the effective portions of changes in the fair value of the derivative are included in other comprehensive income or loss in the consolidated statements of comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. The cumulative changes in fair value are reclassified to the same line as the hedged item in the consolidated statements of operations when the hedged item affects earnings. We evaluate hedge effectiveness at inception and on an ongoing basis, and ineffective portions of changes in the fair value of cash flow hedges and net investment hedges are recognized in earnings following the date when ineffectiveness was identified. In the fourth quarter of 2018, we adopted amended guidance for derivatives and hedging which eliminates the existing requirement to recognize periodic hedge ineffectiveness in earnings for cash flow hedges and net investment hedges that are highly effective. The adoption had no material impact on our financial statements as there was no ineffectiveness recognized on our cash flow hedges or net investment hedges prior to adoption. Derivative instruments not designated as hedges are marked-to-market at the end of each accounting period with the change included in earnings. Comprehensive Income: Comprehensive income consists of two components, net income and other comprehensive income. Other comprehensive income refers to revenue, expenses and gains and losses that under GAAP are recorded as an element of stockholders’ equity but are excluded from earnings. Our other comprehensive income primarily consists of foreign currency translation adjustments from those subsidiaries where the local currency is the functional currency including gains and losses on net investment hedges, unrealized gains and losses on cash flow hedges, as well as unrealized gains and losses on retirement-related benefit plans. Noncontrolling Interests and Redeemable Noncontrolling Interests: Noncontrolling interests represent the portion of profit or loss, net assets and comprehensive income that is not allocable to McKesson Corporation. Net income attributable to noncontrolling interests included recurring compensation that McKesson is obligated to pay to the noncontrolling shareholders of McKesson Europe AG (“McKesson Europe”), formerly known as Celesio AG, under the domination and profit and loss transfer agreement. Net income attributable to noncontrolling interests also included third-party equity interests in our consolidated entities including Vantage Oncology Holdings, LLC (“Vantage”) and ClarusONE Sourcing Services LLP (“ClarusONE”), which was established between McKesson and Walmart, Inc in 2017. Noncontrolling interests with redemption features, such as put rights, that are not solely within the Company’s control are considered redeemable noncontrolling interests. Redeemable noncontrolling interests are presented outside of stockholders’ equity on our consolidated balance sheets. Refer to Financial Note 11, “Redeemable Noncontrolling Interests and Noncontrolling Interests,” for more information. Share-Based Compensation: We account for all share-based compensation transactions at fair value. The share-based compensation expense, for the portion of the awards that is ultimately expected to vest, is recognized on a straight-line basis over the requisite service period. The share-based compensation expense recognized has been classified in the consolidated statements of operations in the same manner as cash compensation paid to our employees. Loss Contingencies: We are subject to various claims, including claims with customers and vendors, pending and potential legal actions for damages, investigations relating to governmental laws and regulations and other matters arising out of the normal conduct of our business. When a loss is considered probable and reasonably estimable, we record a liability in the amount of our best estimate for the ultimate loss. However, the likelihood of a loss with respect to a particular contingency is often difficult to predict and determining a meaningful estimate of the loss or a range of loss may not be practicable based on the information available and the potential effect of future events and decisions by third parties that will determine the ultimate resolution of the contingency. Moreover, it is not uncommon for such matters to be resolved over many years, during which time relevant developments and new information must be reevaluated at least quarterly to determine both the likelihood of potential loss and whether it is possible to reasonably estimate the loss or a range of possible loss. When a material loss is reasonably possible or probable but a reasonable estimate cannot be made, disclosure of the proceeding is provided. We review all contingencies at least quarterly to determine whether the likelihood of loss has changed and to assess whether a reasonable estimate of the loss or a range of the loss can be made. As discussed above, development of a meaningful estimate of loss or a range of potential loss is complex when the outcome is directly dependent on negotiations with or decisions by third parties, such as regulatory agencies, the court system and other interested parties. Restructuring Charges: Employee severance costs are generally recognized when payments are probable and amounts are reasonably estimable. Costs related to contracts without future benefit or contract termination are recognized at the earlier of the contract termination or the cease-use dates. Other exit-related costs are recognized as incurred. Business Combinations: We account for acquired businesses using the acquisition method of accounting, which requires that once control of a business is obtained, 100% of the assets acquired and liabilities assumed, including amounts attributable to noncontrolling interests, be recorded at the date of acquisition at their respective fair values. Any excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Acquisition-related expenses including transaction and integration costs are expensed as incurred. Several valuation methods may be used to determine the fair value of assets acquired and liabilities assumed. For intangible assets, we typically use a method that is a form or variation of the income approach. Income approach methods start with a forecast of all of the expected future net cash flows for each asset. These cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams. Some of the more significant estimates and assumptions inherent in income approach methods include the amount and timing of projected future cash flows, the discount rate selected to measure the risks inherent in the future cash flows and the assessment of the asset’s life cycle and the competitive trends impacting the asset, including consideration of any technical, legal, regulatory, or economic barriers to entry. Determining the useful life of an intangible asset also requires judgment as different types of intangible assets will have different useful lives and certain assets may even be considered to have indefinite useful lives. Recently Adopted Accounting Pronouncements Revenue Recognition: In the first quarter of 2019, we adopted amended guidance for revenue recognition using the modified retrospective method and applied the amended guidance to those contracts which were not completed as of April 1, 2018. The adoption of this amended guidance did not have a material impact on our consolidated financial statements. Our equity method investee, Change Healthcare, is required to adopt the amended guidance in our first quarter of 2020. The adoption of this amended guidance by Change Healthcare is not expected to have a material effect on our consolidated financial statements. We elected the practical expedient to not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less, (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed and (iii) contracts for which the variable consideration is allocated entirely to a wholly unsatisfied performance obligation or to a wholly unsatisfied promise to transfer a distinct good or service that forms part of a single performance obligation. Share-Based Payments: In the first quarter of 2019, we prospectively adopted amended guidance for employee share-based payment awards. This amendment provides guidance on which changes to terms or conditions of a share-based payment award require an entity to apply modification accounting. Under the amended guidance, we are required to account for the effects of a modification of the fair value, the vesting conditions or the classification (as an equity instrument or a liability instrument) of the modified award from that of the original award immediately before the modification. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. Compensation - Retirement Benefits: In the first quarter of 2019, we retrospectively adopted amended guidance which requires us to report the service cost component of defined benefit pension plans and other postretirement plans in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. Other components of net benefit costs are required to be presented in the statements of operations separately from the service cost component outside of operating income. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. This amended guidance only resulted in a change in presentation of other components of net benefit costs on our consolidated statement of operations (a reclassification from operating income to other income, net). Derecognition of Nonfinancial Assets: In the first quarter of 2019, we adopted on a modified retrospective basis amended guidance that defines the term “in substance nonfinancial asset” as a financial asset promised to a counterparty in a contract if substantially all of the fair value of the asset that is promised is concentrated in nonfinancial assets. The scope of this amendment includes nonfinancial assets transferred within a legal entity including a parent entity’s transfer of nonfinancial assets by transferring ownership interests in consolidated subsidiaries. The amendment excludes all businesses and nonprofit activities from its scope and therefore all entities, with limited exceptions, are required to account for the derecognition of a business or nonprofit activity in accordance with the consolidation guidance once this amended guidance becomes effective. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. Business Combinations: In the first quarter of 2019, we prospectively adopted amended guidance that clarifies the definition of a business to assist entities in evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The amended guidance provides a practical screen to determine when an integrated set of assets and activities (collectively referred to as a “set”) is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. If the screen is not met, the amended guidance requires that to be considered a business, a set must include an input and a substantive process that together significantly contribute to the ability to create output. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. Restricted Cash: In the first quarter of 2019, we retrospectively adopted amended guidance that requires restricted cash and restricted cash equivalents to be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total cash amounts shown on the statement of cash flows. Transfers between cash and cash equivalents and restricted cash or restricted cash equivalents are not reported as cash flow activities in the statement of cash flows. Our restricted cash balances at March 31, 2019 and 2018 were not material. The adoption of this amended guidance had no effect on our consolidated statements of operations, comprehensive income or our balance sheets. This amended guidance resulted in a change in presentation of restricted cash on our consolidated statement of cash flows. Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory: In the first quarter of 2019, we adopted on a modified retrospective basis amended guidance that requires entities to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Upon adoption of this amended guidance, we recorded $152 million of deferred tax assets with a corresponding cumulative-effect increase to the beginning balance of retained earnings in our consolidated financial statements for the tax consequences relating to an intra-entity transfer of certain software in December 2016. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments: In the first quarter of 2019, we retrospectively adopted amended guidance that provides clarification on cash flow classification related to eight specific issues including contingent consideration payments made after a business combination and distributions received from equity method investees. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. Financial Instruments: In the first quarter of 2019, we adopted amended guidance that requires investments in equity securities, excluding equity method investments or investees that are consolidated, to be measured at fair value with changes in fair value recognized in net income and enhanced disclosures about those investments. The amended guidance also simplifies the impairment assessments of equity investments without readily determinable fair value. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted Collaborative Arrangements: In November 2018, amended guidance was issued which clarifies that certain transactions between participants in a collaborative arrangement should be accounted for under revenue recognition guidance when the counterparty is a customer. The amended guidance is effective for us in the first quarter of 2021 on a retrospective basis with a cumulative-effect adjustment to beginning retained earnings. We may elect to apply this amended guidance retrospectively either to all contracts or only to contracts that are not completed at the date of initial adoption. Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements. Derivatives and Hedging: In October 2018, amended guidance was issued which allowed for the inclusion of the Secured Overnight Financing Rate Overnight Index Swap Rate as a benchmark interest rate for hedge accounting purposes. The amended guidance is effective for us on a prospective basis for qualifying new or redesignated hedging relationships entered into on or after the first quarter of 2020. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material impact on our consolidated financial statements. Disclosure Update and Simplification: In August 2018, the Securities and Exchange Commission (“SEC”) issued a final rule to simplify certain disclosure requirements. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders’ equity for interim financial statements. In August and September 2018, further amendments were issued to provide implementation and transition guidance on adoption of this SEC rule. The amended guidance is effective for us commencing in the first quarter of 2020. We do not expect the adoption of this amended guidance to have a material effect on our consolidated statements of operations, comprehensive income, balance sheets or cash flows. This amended guidance will result in changes in disclosures. Intangibles - Goodwill and Other - Internal-Use Software: In August 2018, amended guidance was issued for a customer’s accounting for implementation and other upfront costs incurred in a cloud computing arrangement that is a service contract. The amended guidance aligns the requirements for capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract with the requirements for capitalizing implementation costs for a cloud computing arrangement that has a software license. The amended guidance is effective for us either on a retrospective or prospective basis commencing in the first quarter of 2021. Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements. Compensation - Retirement Benefits - Defined Benefit Plans: In August 2018, amended guidance was issued for defined benefit pension or other postretirement plans. The amended guidance requires us to disclose the weighted-average interest crediting rates for cash balance plans and other plans with promised interest crediting rates, and an explanation of reasons for significant gains and losses related to changes in the benefit obligation for the period. The amended guidance also requires us to remove disclosures on the amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit costs over the next fiscal year. The amended guidance is effective for us on a retrospective basis commencing in the fiscal year ended March 31, 2021. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated statements of operations, comprehensive income, balance sheets or cash flows. This amended guidance will result in changes in disclosures. Fair Value Measurement: In August 2018, amended guidance was issued to remove, modify and add disclosure requirements on the fair value measurements. The amended guidance removes disclosure requirements for transfers between Level 1 and Level 2 measurements and valuation processes for Level 3 measurements but adds new disclosure requirements including changes in unrealized gains or losses in other comprehensive income related to recurring Level 3 measurements. The amended guidance is effective for us commencing in the first quarter of 2021. Certain requirements will be applied prospectively while other changes will be applied retrospectively upon the effective date. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated statements of operations, comprehensive income, balance sheets or cash flows. This amended guidance will result in changes in disclosures. Accumulated Other Comprehensive Income: In February 2018, amended guidance was issued to address a narrow-scope financial reporting issue that arose as a consequence of the 2017 Tax Cuts and Jobs Act (the “2017 Tax Act”). Existing guidance requires that deferred tax liabilities and assets be adjusted for a change in tax laws with the effect included in income from continuing operations in the reporting period that includes the enactment date. That guidance is applicable even in situations in which the related income tax effects of items in accumulated other comprehensive income were originally recognized in other comprehensive income rather than in net income, such as amounts related to benefit plans and hedging activity. As a result, the tax effects of items within accumulated other comprehensive income do not reflect the appropriate tax rate. These differences are referred to as stranded tax effects. The amended guidance allows for a reclassification of only those amounts related to the 2017 Tax Act to retained earnings thereby eliminating the stranded tax effects. The amended guidance also requires certain disclosures about stranded tax effects. The amended guidance is effective for us commencing in the first quarter of 2020 on a prospective or retrospective basis. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated financial statements. Premium Amortization of Purchased Callable Debt Securities: In March 2017, amended guidance was issued to shorten the amortization period for certain callable debt securities held at a premium. The amended guidance requires the premium of callable debt securities to be amortized to the earliest call date but does not require an accounting change for securities held at a discount as they would still be amortized to maturity. The amended guidance is effective for us on a modified retrospective basis commencing in the first quarter of 2020. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated financial statements. Financial Instruments - Credit Losses: In June 2016, amended guidance was issued, which will change the impairment model for most financial assets and require additional disclosures. The amended guidance requires financial assets that are measured at amortized cost be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of financial assets. The amended guidance also requires us to consider historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount in estimating credit losses. The amended guidance becomes effective for us commencing in the first quarter of 2021 and will be applied through a cumulative-effect adjustment to the beginning retained earnings in the year of adoption. Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements. Leases: In February 2016, amended guidance was issued for lease arrangements. The amended guidance requires lessees to recognize lease liabilities and right-of-use (“ROU”) assets on the balance sheet for all leases and to provide enhanced disclosures on key information of leasing arrangements. The amended guidance is effective for us commencing in the first quarter of 2020. Early adoption is permitted. We will adopt the amended guidance on a modified retrospective basis through a cumulative-effect adjustment to the beginning retained earnings in the period of adoption. We will elect the transition package of practical expedients provided within the amended guidance, which eliminates the requirements to reassess lease identification, lease classification and initial direct costs for leases commenced before the effective date. The Company will also elect not to separate lease from non-lease components and to exclude short-term leases from its consolidated balance sheets. The adoption of the amended guidance is expected to have a material impact on our consolidated balance sheet from the recognition of lease assets and liabilities. While we continue to assess all the impacts of adoption, we anticipate recognizing operating lease liabilities in excess of $2.0 billion based on the present value of the remaining minimum lease commitments using our incremental borrowing rate as of the effective date under the full lease term. We also expect to record corresponding ROU assets based upon the operating lease liabilities adjusted for prepaid and deferred rents, unamortized initial direct costs, liabilities associated with lease termination costs and impairments of ROU assets recognized to opening retained earnings at the effective date. Additionally, existing deferred gain on our sale-leaseback transaction will be derecognized from the consolidated balance sheet and recognized to opening retained earnings at the effective date. While we have not completed our evaluation of impairments of ROU assets upon adoption, we anticipate that the historical impairments of certain retail pharmacy stores in the historical periods prior to adoption will result in impairments of retail store ROU assets recognized through retained earnings upon adoption. We are finalizing the impact that the amended lease guidance will have on our consolidated financial statements, systems, processes and internal controls.

Significant Accounting Policies

Nature of Operations: McKesson Corporation (“McKesson,” the “Company,” the “Registrant” or “we” and other similar pronouns) delivers a comprehensive offering of pharmaceuticals and medical supplies and provides services to help our customers improve the efficiency and effectiveness of their healthcare operations. Commencing in the first quarter of 2019, our new segment reporting structure was implemented and we have reported our financial results in three reportable segments on a retrospective basis: U.S. Pharmaceutical and Specialty Solutions, European Pharmaceutical Solutions and Medical-Surgical Solutions. All remaining operating segments and business activities that are not significant enough to require separate reportable segment disclosure are included in Other. Refer to Financial Note 28, “Segments of Business” for more information.

Basis of Presentation: The consolidated financial statements and accompanying notes are prepared in accordance with U. S. generally accepted accounting principles (“GAAP”). The consolidated financial statements of McKesson include the financial statements of all wholly-owned subsidiaries and majority-owned or controlled companies. For those consolidated subsidiaries where our ownership is less than 100%, the portion of the net income or loss allocable to the noncontrolling interests is reported as “Net Income Attributable to Noncontrolling Interests” on the consolidated statements of operations. All significant intercompany balances and transactions have been eliminated in consolidation including the intercompany portion of transactions with equity method investees.

We consider ourselves to control an entity if we are the majority owner of or have voting control over such entity. We also assess control through means other than voting rights (“variable interest entities” or “VIEs”) and determine which business entity is the primary beneficiary of the VIE. We consolidate VIEs when it is determined that we are the primary beneficiary of the VIE. Investments in business entities in which we do not have control but have the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method. Refer to Financial Note 5, “Healthcare Technology Net Asset Exchange” for further information on our equity method investment in Change Healthcare, LLC (“Change Healthcare”).

Fiscal Period: The Company’s fiscal year begins on April 1 and ends on March 31. Unless otherwise noted, all references to a particular year shall mean the Company’s fiscal year.

Reclassifications: Certain prior year amounts have been reclassified to conform to the current year presentation.

Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires that we make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimated amounts.

Cash and Cash Equivalents: All highly liquid debt and money market instruments purchased with original maturity of three months or less at the date of acquisition are included in cash and cash equivalents. Cash equivalents are carried at fair value. Cash equivalents are primarily invested in AAA rated prime and U.S. government money market funds denominated in U.S. dollars, overnight repurchase agreements collateralized by U.S. government securities, Canadian government securities and/or securities that are guaranteed or sponsored by the U.S. government and an AAA rated prime money market fund denominated in British pound sterling. The remaining cash and cash equivalents are deposited with several financial institutions. Deposits may exceed the amounts insured by the Federal Deposit Insurance Corporation in the U.S. and similar deposit insurance programs in other jurisdictions. We mitigate the risk of our short-term investment portfolio by depositing funds with reputable financial institutions and monitoring risk profiles and investment strategies of money market funds.

Restricted Cash: Cash that is subject to legal restrictions or is unavailable for general operating purposes is classified as restricted cash and is included within “Prepaid expenses and other” and “Other Noncurrent Assets” in the consolidated balance sheets. At March 31, 2019 and 2018, our restricted cash balance was not material.

Marketable Securities Available-for-Sale: Our marketable securities, which are available-for-sale, are carried at fair value and are included within “Prepaid expenses and other” in the consolidated balance sheets. The unrealized gains and losses, net of the related tax effect, computed in marking these securities to market have been reported within stockholders’ equity. At March 31, 2019 and 2018, marketable securities were not material. In determining whether an other-than-temporary decline in market value has occurred, we consider the duration that, and extent to which, the fair value of the investment is below its cost, the financial condition and future prospects of the issuer or underlying collateral of a security, and our intent and ability to retain the security in order to allow for an anticipated recovery in fair value. Other-than-temporary declines in fair value from amortized cost for available-for-sale equity securities that we intend to sell or would more likely than not be required to sell before the expected recovery of the amortized cost basis are charged to other income, net, in the period in which the loss occurs.

Equity Method Investments: Investments in business entities in which we do not have control, but have the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method. We evaluate our equity method investments for impairment whenever an event or change in circumstances occurs that may have a significant adverse impact on the carrying value of the investment. If a loss in value has occurred that is deemed to be other-than-temporary, an impairment loss is recorded. Refer to Financial Note 5, “Healthcare Technology Net Asset Exchange” for further information relating to our equity method investment in Change Healthcare, LLC (“Change Healthcare”).

Concentrations of Credit Risk and Receivables: Our trade accounts receivable are subject to concentrations of credit risk with customers primarily in our U.S. Pharmaceutical and Specialty Solutions segment. During 2019, sales to our ten largest customers, including group purchasing organizations (“GPOs”) accounted for approximately 49.9% of our total consolidated revenues. Sales to our largest customer, CVS Health (“CVS”), accounted for approximately 19.4% of our total consolidated revenues. At March 31, 2019, trade accounts receivable from our ten largest customers were approximately 31.9% of total trade accounts receivable. Accounts receivable from CVS were approximately 18.4% of total trade accounts receivable. As a result, our sales and credit concentration is significant. We also have agreements with GPOs, each of which functions as a purchasing agent on behalf of member hospitals, pharmacies and other healthcare providers, as well as with government entities and agencies. The accounts receivables balances are with individual members of the GPOs, and therefore no significant concentration of credit risk exists. A material default in payment, a material reduction in purchases from these or any other large customers, or the loss of a large customer or customer groups could have a material adverse impact on our financial condition, results of operations and liquidity. In addition, trade receivables are subject to concentrations of credit risk with customers in the institutional, retail and healthcare provider sectors, which can be affected by a downturn in the economy and changes in reimbursement policies. This credit risk is mitigated by the size and diversity of the customer base as well as its geographic dispersion. We estimate the receivables for which we do not expect full collection based on historical collection rates and ongoing evaluations of the creditworthiness of our customers. An allowance is recorded in our consolidated financial statements for these estimated amounts.

Financing Receivables: We assess and monitor credit risk associated with financing receivables, primarily notes receivables, through regular review of our collection experience in determining our allowance for loan losses. On an ongoing basis, we also evaluate credit quality of our financing receivables utilizing aging of receivables and write-offs, as well as considering existing economic conditions, to determine if an allowance is required. Financing receivables are derecognized if legal title to them has been transferred and all related risks and rewards incidental to ownership have passed to the buyer. As of March 31, 2019 and 2018, financing receivables and the related allowance were not material to our consolidated financial statements.

Inventories: Inventories consist of merchandise held for resale. Prior to 2018, we reported inventories at the lower of cost or market (“LCM”). Effective in the first quarter of 2018, we report inventories at the lower of cost or net realizable value, except for inventories determined using the last-in, first-out (“LIFO”) method. The majority of the cost of domestic inventories is determined using the LIFO method. The majority of the cost of inventories held in foreign locations is based on first-in, first-out method and weighted average purchase prices. Rebates, cash discounts, and other incentives received from vendors are recognized within cost of sales upon the sale of the related inventory.

The LIFO method was used to value approximately 62% and 63% of our inventories at March 31, 2019 and 2018. If we had used the moving average method of inventory valuation, inventories would have been approximately $696 million and $906 million higher than the amounts reported at March 31, 2019 and 2018. These amounts are equivalent to our LIFO reserves. Our LIFO valuation amount includes both pharmaceutical and non-pharmaceutical products. We recognized LIFO credits of $210 million, $99 million and $7 million in 2019, 2018 and 2017 in cost of sales within our consolidated statements of operations. A LIFO charge is recognized when the net effect of price increases on pharmaceutical and non-pharmaceutical products held in inventory exceeds the impact of price declines, including the effect of branded pharmaceutical products that have lost market exclusivity. A LIFO credit is recognized when the net effect of price declines exceeds the impact of price increases on pharmaceutical and non-pharmaceutical products held in inventory.

We believe that moving average inventory costing method provides a reasonable estimation of the current cost of replacing inventory (i.e., “market”). As such, our LIFO inventory is valued at the lower of LIFO cost or market. As of March 31, 2019 and 2018, inventories at LIFO did not exceed market.

Shipping and Handling Costs: We include costs to pack and deliver inventory to our customers in selling, distribution and administrative expenses. Shipping and handling costs of $951 million, $914 million, and $814 million were recognized in 2019, 2018 and 2017.

Property, Plant and Equipment: We state our property, plant and equipment (“PPE”) at cost and depreciate them under the straight-line method at rates designed to distribute the cost of PPE over estimated service lives ranging from one to thirty years. When certain events or changes in operating conditions occur, an impairment assessment may be performed on the recoverability of the carrying amounts.

Goodwill: Goodwill is tested for impairment on an annual basis in the fourth quarter or more frequently if indicators of potential impairment exist. Impairment testing is conducted at the reporting unit level, which is generally defined as an operating segment or one level below an operating segment (also known as a component), for which discrete financial information is available and segment management regularly reviews the operating results of that reporting unit.

The goodwill testing requires us to compare the estimated fair value of a reporting unit to its carrying value. If the carrying value of the reporting unit is lower than its estimated fair value, no further evaluation is required. If the carrying value of the reporting unit exceeds its estimated fair value, an impairment charge is recorded for that excess, limited to the total amount of goodwill allocated to that reporting unit.

To estimate the fair value of our reporting units, we generally use a combination of the market approach and the income approach. Under the market approach, we estimate fair value by comparing the business to similar businesses or guideline companies whose securities are actively traded in public markets. Under the income approach, we use a discounted cash flow (“DCF”) model in which cash flows anticipated over future periods, plus a terminal value at the end of that time horizon, are discounted to their present value using an estimated expected rate of return. Other estimates inherent in both the market and income approaches include long-term growth rates, projected revenues, earnings and cash flow forecasts for the reporting units. In addition, we compare the aggregate of the reporting units’ fair values to the Company’s market capitalization as a further corroboration of the fair values. Goodwill testing requires a complex series of assumptions and judgments by management in projecting future operating results, selecting guideline companies for comparisons and assessing risks. The use of alternative assumptions and estimates could affect the fair values and change the impairment determinations.

Intangible Assets: Currently all of our intangible assets are subject to amortization and are amortized based on the pattern of their economic consumption or on a straight-line basis over their estimated useful lives, ranging from one to 38 years. We review intangible assets for impairment at an asset group level whenever events or changes in circumstances indicate that the carrying value of the assets may not be recoverable. Determination of recoverability is based on the lowest level of identifiable estimated future undiscounted cash flows resulting from use of the asset and its eventual disposition. Measurement of any impairment loss is based on the excess of the carrying value of the asset group over its estimated fair market value.

Capitalized Software Held for Internal Use: We capitalize costs of software held for internal use during the application development stage of a project and amortize those costs over their estimated useful lives ranging from one to ten years. As of March 31, 2019 and 2018, capitalized software held for internal use was $394 million and $425 million, net of accumulated amortization of $1,246 million and $1,182 million, and was included in other noncurrent assets in the consolidated balance sheets.

Insurance Programs: Under our insurance programs, we seek to obtain coverage for catastrophic exposures as well as those risks required to be insured by law or contract. It is our policy to retain a significant portion of certain losses primarily related to workers’ compensation and comprehensive general, product and vehicle liability. Provisions for losses expected under these programs are recorded based on our estimate of the aggregate liability for claims incurred as well as for claims incurred but not yet reported. Such estimates utilize certain actuarial assumptions followed in the insurance industry.

Revenue Recognition: Revenue is recognized when an entity satisfies a performance obligation by transferring control of a promised good or service to a customer in an amount that reflects the consideration to which the entity expects to be entitled for that good or service.

Revenues generated from the distribution of pharmaceutical and medical products represent the majority of our revenues. We order product from the manufacturer, receive and carry the product at our central distribution facilities and deliver the product directly to our customers’ warehouses, hospitals or retail pharmacies. The distribution business primarily generates revenue from a contract related to a confirmed purchase order with a customer in a distribution arrangement. Revenue is recognized when control of goods is transferred to the customer which occurs upon our delivery to the customer or upon customer pick-up. We also earn revenues from a variety of other sources including our retail, services and technology businesses. Retail revenues are recognized at the point of sale. Service revenues, including technology service revenues, are recognized when services are rendered. Revenues derived from distribution and retail business at the point of sale, and revenues derived from services represent approximately 98% and 2% of total revenues for the year ended on March 31, 2019.

Revenues are recorded gross when we are the principal in the transaction, have the ability to direct the use of the goods or services prior to transfer to a customer, are responsible for fulfilling the promise to our customer, have latitude in establishing prices, and control the relationship with the customer. We record our revenues net of sales taxes. Revenues are measured based on the amount of consideration that we expect to receive, reduced by estimates for return allowances, discounts and rebates using historical data. Sales returns from customers were approximately $2.9 billion in 2019, and $3.1 billion in 2018 and 2017. Assets for the right to recover products from customers and the associated refund liabilities for return allowances were not material as of March 31, 2019. Shipping and handling costs associated with outbound freight after control over a product has transferred to a customer are accounted for as fulfillment costs and are included in selling, distribution and administrative expenses. We record deferred revenues when payments are received or due in advance of our performance. Deferred revenues are primarily from our services arrangements and are recognized as revenues over the periods when services are performed.

We had no material contract assets, contract liabilities or deferred contract costs recorded on the consolidated balance sheets.

We elected the practical expedient and generally expense costs to obtain a contract when incurred because the amortization period would have been one year or less.

Supplier Incentives: Fees for services and other incentives received from suppliers, relating to the purchase or distribution of inventory, are considered product discounts and are generally reported as a reduction to cost of sales.

Supplier Reserves: We establish reserves against amounts due from suppliers relating to various fees for services and price and rebate incentives, including deductions taken against payments otherwise due to them. These reserve estimates are established based on judgment after considering the status of current outstanding claims, historical experience with the suppliers, the specific incentive programs and any other pertinent information available. We evaluate the amounts due from suppliers on a continual basis and adjust the reserve estimates when appropriate based on changes in facts and circumstances. Adjustments to supplier reserves are generally included within cost of sales. The ultimate outcome of any outstanding claims may be different than our estimate. The supplier reserves primarily pertain to our U.S. Pharmaceutical and Specialty Solutions segment.

Income Taxes: We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or the tax returns. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statements and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. The amount recognized is measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon effective settlement. Deferred taxes are not provided on undistributed earnings of our foreign operations that are considered to be permanently reinvested.

Foreign Currency Translation: The reporting currency of the Company and its subsidiaries is the U.S. dollar. Our foreign subsidiaries generally consider their local currency to be their functional currency. Foreign currency-denominated assets and liabilities of these foreign subsidiaries are translated into U.S. dollars at period-end exchange rates, while revenues and expenses are translated at average exchange rates during the corresponding period and stockholders’ equity accounts are primarily translated at historical exchange rates. Foreign currency translation adjustments are included in other comprehensive income or loss in the consolidated statements of comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. Realized gains and losses from currency exchange transactions are recorded in operating expenses in the consolidated statements of operations and were not material to our consolidated results of operations in 2019, 2018 or 2017. We release cumulative translation adjustments from stockholders’ equity into earnings as a gain or loss only upon complete or substantially complete liquidation of a controlling interest in a subsidiary or a group of assets within a foreign entity. We also release all or a pro rata portion of the cumulative translation adjustments into earnings upon the sale of an equity method investment that is a foreign entity.

Derivative Financial Instruments: Derivative financial instruments are used principally in the management of foreign currency exchange and interest rate exposures and are recorded on the consolidated balance sheets at fair value. If a derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized in earnings. We use foreign currency-denominated notes and cross-currency swaps to hedge a portion of our net investment in our foreign subsidiaries. We use cash flow hedges primarily to reduce the effects of foreign currency exchange rate risk related to intercompany loans denominated in non-functional currencies. If the financial instrument is designated as a cash flow hedge or net investment hedge, the effective portions of changes in the fair value of the derivative are included in other comprehensive income or loss in the consolidated statements of comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. The cumulative changes in fair value are reclassified to the same line as the hedged item in the consolidated statements of operations when the hedged item affects earnings. We evaluate hedge effectiveness at inception and on an ongoing basis, and ineffective portions of changes in the fair value of cash flow hedges and net investment hedges are recognized in earnings following the date when ineffectiveness was identified. In the fourth quarter of 2018, we adopted amended guidance for derivatives and hedging which eliminates the existing requirement to recognize periodic hedge ineffectiveness in earnings for cash flow hedges and net investment hedges that are highly effective. The adoption had no material impact on our financial statements as there was no ineffectiveness recognized on our cash flow hedges or net investment hedges prior to adoption. Derivative instruments not designated as hedges are marked-to-market at the end of each accounting period with the change included in earnings.

Comprehensive Income: Comprehensive income consists of two components, net income and other comprehensive income. Other comprehensive income refers to revenue, expenses and gains and losses that under GAAP are recorded as an element of stockholders’ equity but are excluded from earnings. Our other comprehensive income primarily consists of foreign currency translation adjustments from those subsidiaries where the local currency is the functional currency including gains and losses on net investment hedges, unrealized gains and losses on cash flow hedges, as well as unrealized gains and losses on retirement-related benefit plans.

Noncontrolling Interests and Redeemable Noncontrolling Interests: Noncontrolling interests represent the portion of profit or loss, net assets and comprehensive income that is not allocable to McKesson Corporation. Net income attributable to noncontrolling interests included recurring compensation that McKesson is obligated to pay to the noncontrolling shareholders of McKesson Europe AG (“McKesson Europe”), formerly known as Celesio AG, under the domination and profit and loss transfer agreement. Net income attributable to noncontrolling interests also included third-party equity interests in our consolidated entities including Vantage Oncology Holdings, LLC (“Vantage”) and ClarusONE Sourcing Services LLP (“ClarusONE”), which was established between McKesson and Walmart, Inc in 2017. Noncontrolling interests with redemption features, such as put rights, that are not solely within the Company’s control are considered redeemable noncontrolling interests. Redeemable noncontrolling interests are presented outside of stockholders’ equity on our consolidated balance sheets. Refer to Financial Note 11, “Redeemable Noncontrolling Interests and Noncontrolling Interests,” for more information.

Share-Based Compensation: We account for all share-based compensation transactions at fair value. The share-based compensation expense, for the portion of the awards that is ultimately expected to vest, is recognized on a straight-line basis over the requisite service period. The share-based compensation expense recognized has been classified in the consolidated statements of operations in the same manner as cash compensation paid to our employees.

Loss Contingencies: We are subject to various claims, including claims with customers and vendors, pending and potential legal actions for damages, investigations relating to governmental laws and regulations and other matters arising out of the normal conduct of our business. When a loss is considered probable and reasonably estimable, we record a liability in the amount of our best estimate for the ultimate loss. However, the likelihood of a loss with respect to a particular contingency is often difficult to predict and determining a meaningful estimate of the loss or a range of loss may not be practicable based on the information available and the potential effect of future events and decisions by third parties that will determine the ultimate resolution of the contingency. Moreover, it is not uncommon for such matters to be resolved over many years, during which time relevant developments and new information must be reevaluated at least quarterly to determine both the likelihood of potential loss and whether it is possible to reasonably estimate the loss or a range of possible loss. When a material loss is reasonably possible or probable but a reasonable estimate cannot be made, disclosure of the proceeding is provided.

We review all contingencies at least quarterly to determine whether the likelihood of loss has changed and to assess whether a reasonable estimate of the loss or a range of the loss can be made. As discussed above, development of a meaningful estimate of loss or a range of potential loss is complex when the outcome is directly dependent on negotiations with or decisions by third parties, such as regulatory agencies, the court system and other interested parties.

Restructuring Charges: Employee severance costs are generally recognized when payments are probable and amounts are reasonably estimable. Costs related to contracts without future benefit or contract termination are recognized at the earlier of the contract termination or the cease-use dates. Other exit-related costs are recognized as incurred.

Business Combinations: We account for acquired businesses using the acquisition method of accounting, which requires that once control of a business is obtained, 100% of the assets acquired and liabilities assumed, including amounts attributable to noncontrolling interests, be recorded at the date of acquisition at their respective fair values. Any excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Acquisition-related expenses including transaction and integration costs are expensed as incurred.

Several valuation methods may be used to determine the fair value of assets acquired and liabilities assumed. For intangible assets, we typically use a method that is a form or variation of the income approach. Income approach methods start with a forecast of all of the expected future net cash flows for each asset. These cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams. Some of the more significant estimates and assumptions inherent in income approach methods include the amount and timing of projected future cash flows, the discount rate selected to measure the risks inherent in the future cash flows and the assessment of the asset’s life cycle and the competitive trends impacting the asset, including consideration of any technical, legal, regulatory, or economic barriers to entry. Determining the useful life of an intangible asset also requires judgment as different types of intangible assets will have different useful lives and certain assets may even be considered to have indefinite useful lives.

Recently Adopted Accounting Pronouncements

Revenue Recognition: In the first quarter of 2019, we adopted amended guidance for revenue recognition using the modified retrospective method and applied the amended guidance to those contracts which were not completed as of April 1, 2018. The adoption of this amended guidance did not have a material impact on our consolidated financial statements. Our equity method investee, Change Healthcare, is required to adopt the amended guidance in our first quarter of 2020. The adoption of this amended guidance by Change Healthcare is not expected to have a material effect on our consolidated financial statements.

We elected the practical expedient to not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less, (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed and (iii) contracts for which the variable consideration is allocated entirely to a wholly unsatisfied performance obligation or to a wholly unsatisfied promise to transfer a distinct good or service that forms part of a single performance obligation.

Share-Based Payments: In the first quarter of 2019, we prospectively adopted amended guidance for employee share-based payment awards. This amendment provides guidance on which changes to terms or conditions of a share-based payment award require an entity to apply modification accounting. Under the amended guidance, we are required to account for the effects of a modification of the fair value, the vesting conditions or the classification (as an equity instrument or a liability instrument) of the modified award from that of the original award immediately before the modification. The adoption of this amended guidance did not have a material effect on our consolidated financial statements.

Compensation - Retirement Benefits: In the first quarter of 2019, we retrospectively adopted amended guidance which requires us to report the service cost component of defined benefit pension plans and other postretirement plans in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. Other components of net benefit costs are required to be presented in the statements of operations separately from the service cost component outside of operating income. The adoption of this amended guidance did not have a material effect on our consolidated financial statements. This amended guidance only resulted in a change in presentation of other components of net benefit costs on our consolidated statement of operations (a reclassification from operating income to other income, net).

Derecognition of Nonfinancial Assets: In the first quarter of 2019, we adopted on a modified retrospective basis amended guidance that defines the term “in substance nonfinancial asset” as a financial asset promised to a counterparty in a contract if substantially all of the fair value of the asset that is promised is concentrated in nonfinancial assets. The scope of this amendment includes nonfinancial assets transferred within a legal entity including a parent entity’s transfer of nonfinancial assets by transferring ownership interests in consolidated subsidiaries. The amendment excludes all businesses and nonprofit activities from its scope and therefore all entities, with limited exceptions, are required to account for the derecognition of a business or nonprofit activity in accordance with the consolidation guidance once this amended guidance becomes effective. The adoption of this amended guidance did not have a material effect on our consolidated financial statements.

Business Combinations: In the first quarter of 2019, we prospectively adopted amended guidance that clarifies the definition of a business to assist entities in evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The amended guidance provides a practical screen to determine when an integrated set of assets and activities (collectively referred to as a “set”) is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. If the screen is not met, the amended guidance requires that to be considered a business, a set must include an input and a substantive process that together significantly contribute to the ability to create output. The adoption of this amended guidance did not have a material effect on our consolidated financial statements.

Restricted Cash: In the first quarter of 2019, we retrospectively adopted amended guidance that requires restricted cash and restricted cash equivalents to be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total cash amounts shown on the statement of cash flows. Transfers between cash and cash equivalents and restricted cash or restricted cash equivalents are not reported as cash flow activities in the statement of cash flows. Our restricted cash balances at March 31, 2019 and 2018 were not material. The adoption of this amended guidance had no effect on our consolidated statements of operations, comprehensive income or our balance sheets. This amended guidance resulted in a change in presentation of restricted cash on our consolidated statement of cash flows.

Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory: In the first quarter of 2019, we adopted on a modified retrospective basis amended guidance that requires entities to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Upon adoption of this amended guidance, we recorded $152 million of deferred tax assets with a corresponding cumulative-effect increase to the beginning balance of retained earnings in our consolidated financial statements for the tax consequences relating to an intra-entity transfer of certain software in December 2016.

Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments: In the first quarter of 2019, we retrospectively adopted amended guidance that provides clarification on cash flow classification related to eight specific issues including contingent consideration payments made after a business combination and distributions received from equity method investees. The adoption of this amended guidance did not have a material effect on our consolidated financial statements.

Financial Instruments: In the first quarter of 2019, we adopted amended guidance that requires investments in equity securities, excluding equity method investments or investees that are consolidated, to be measured at fair value with changes in fair value recognized in net income and enhanced disclosures about those investments. The amended guidance also simplifies the impairment assessments of equity investments without readily determinable fair value. The adoption of this amended guidance did not have a material effect on our consolidated financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

Collaborative Arrangements: In November 2018, amended guidance was issued which clarifies that certain transactions between participants in a collaborative arrangement should be accounted for under revenue recognition guidance when the counterparty is a customer. The amended guidance is effective for us in the first quarter of 2021 on a retrospective basis with a cumulative-effect adjustment to beginning retained earnings. We may elect to apply this amended guidance retrospectively either to all contracts or only to contracts that are not completed at the date of initial adoption. Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements.

Derivatives and Hedging: In October 2018, amended guidance was issued which allowed for the inclusion of the Secured Overnight Financing Rate Overnight Index Swap Rate as a benchmark interest rate for hedge accounting purposes. The amended guidance is effective for us on a prospective basis for qualifying new or redesignated hedging relationships entered into on or after the first quarter of 2020. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material impact on our consolidated financial statements.

Disclosure Update and Simplification: In August 2018, the Securities and Exchange Commission (“SEC”) issued a final rule to simplify certain disclosure requirements. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders’ equity for interim financial statements. In August and September 2018, further amendments were issued to provide implementation and transition guidance on adoption of this SEC rule. The amended guidance is effective for us commencing in the first quarter of 2020. We do not expect the adoption of this amended guidance to have a material effect on our consolidated statements of operations, comprehensive income, balance sheets or cash flows. This amended guidance will result in changes in disclosures.

Intangibles - Goodwill and Other - Internal-Use Software: In August 2018, amended guidance was issued for a customer’s accounting for implementation and other upfront costs incurred in a cloud computing arrangement that is a service contract. The amended guidance aligns the requirements for capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract with the requirements for capitalizing implementation costs for a cloud computing arrangement that has a software license. The amended guidance is effective for us either on a retrospective or prospective basis commencing in the first quarter of 2021. Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements.

Compensation - Retirement Benefits - Defined Benefit Plans: In August 2018, amended guidance was issued for defined benefit pension or other postretirement plans. The amended guidance requires us to disclose the weighted-average interest crediting rates for cash balance plans and other plans with promised interest crediting rates, and an explanation of reasons for significant gains and losses related to changes in the benefit obligation for the period. The amended guidance also requires us to remove disclosures on the amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit costs over the next fiscal year. The amended guidance is effective for us on a retrospective basis commencing in the fiscal year ended March 31, 2021. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated statements of operations, comprehensive income, balance sheets or cash flows. This amended guidance will result in changes in disclosures.

Fair Value Measurement: In August 2018, amended guidance was issued to remove, modify and add disclosure requirements on the fair value measurements. The amended guidance removes disclosure requirements for transfers between Level 1 and Level 2 measurements and valuation processes for Level 3 measurements but adds new disclosure requirements including changes in unrealized gains or losses in other comprehensive income related to recurring Level 3 measurements. The amended guidance is effective for us commencing in the first quarter of 2021. Certain requirements will be applied prospectively while other changes will be applied retrospectively upon the effective date. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated statements of operations, comprehensive income, balance sheets or cash flows. This amended guidance will result in changes in disclosures.

Accumulated Other Comprehensive Income: In February 2018, amended guidance was issued to address a narrow-scope financial reporting issue that arose as a consequence of the 2017 Tax Cuts and Jobs Act (the “2017 Tax Act”). Existing guidance requires that deferred tax liabilities and assets be adjusted for a change in tax laws with the effect included in income from continuing operations in the reporting period that includes the enactment date. That guidance is applicable even in situations in which the related income tax effects of items in accumulated other comprehensive income were originally recognized in other comprehensive income rather than in net income, such as amounts related to benefit plans and hedging activity. As a result, the tax effects of items within accumulated other comprehensive income do not reflect the appropriate tax rate. These differences are referred to as stranded tax effects. The amended guidance allows for a reclassification of only those amounts related to the 2017 Tax Act to retained earnings thereby eliminating the stranded tax effects. The amended guidance also requires certain disclosures about stranded tax effects. The amended guidance is effective for us commencing in the first quarter of 2020 on a prospective or retrospective basis. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated financial statements.

Premium Amortization of Purchased Callable Debt Securities: In March 2017, amended guidance was issued to shorten the amortization period for certain callable debt securities held at a premium. The amended guidance requires the premium of callable debt securities to be amortized to the earliest call date but does not require an accounting change for securities held at a discount as they would still be amortized to maturity. The amended guidance is effective for us on a modified retrospective basis commencing in the first quarter of 2020. Early adoption is permitted. We do not expect the adoption of this amended guidance to have a material effect on our consolidated financial statements.

Financial Instruments - Credit Losses: In June 2016, amended guidance was issued, which will change the impairment model for most financial assets and require additional disclosures. The amended guidance requires financial assets that are measured at amortized cost be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of financial assets. The amended guidance also requires us to consider historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount in estimating credit losses. The amended guidance becomes effective for us commencing in the first quarter of 2021 and will be applied through a cumulative-effect adjustment to the beginning retained earnings in the year of adoption. Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements.

Leases: In February 2016, amended guidance was issued for lease arrangements. The amended guidance requires lessees to recognize lease liabilities and right-of-use (“ROU”) assets on the balance sheet for all leases and to provide enhanced disclosures on key information of leasing arrangements. The amended guidance is effective for us commencing in the first quarter of 2020. Early adoption is permitted. We will adopt the amended guidance on a modified retrospective basis through a cumulative-effect adjustment to the beginning retained earnings in the period of adoption.

We will elect the transition package of practical expedients provided within the amended guidance, which eliminates the requirements to reassess lease identification, lease classification and initial direct costs for leases commenced before the effective date. The Company will also elect not to separate lease from non-lease components and to exclude short-term leases from its consolidated balance sheets.

The adoption of the amended guidance is expected to have a material impact on our consolidated balance sheet from the recognition of lease assets and liabilities. While we continue to assess all the impacts of adoption, we anticipate recognizing operating lease liabilities in excess of $2.0 billion based on the present value of the remaining minimum lease commitments using our incremental borrowing rate as of the effective date under the full lease term. We also expect to record corresponding ROU assets based upon the operating lease liabilities adjusted for prepaid and deferred rents, unamortized initial direct costs, liabilities associated with lease termination costs and impairments of ROU assets recognized to opening retained earnings at the effective date. Additionally, existing deferred gain on our sale-leaseback transaction will be derecognized from the consolidated balance sheet and recognized to opening retained earnings at the effective date. While we have not completed our evaluation of impairments of ROU assets upon adoption, we anticipate that the historical impairments of certain retail pharmacy stores in the historical periods prior to adoption will result in impairments of retail store ROU assets recognized through retained earnings upon adoption. We are finalizing the impact that the amended lease guidance will have on our consolidated financial statements, systems, processes and internal controls.