NOTE A  BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements of Boston Scientific Corporation have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. When used in this report, the terms, "we," "us," "our," and "the Company" mean Boston Scientific Corporation and its divisions and subsidiaries. In the opinion of management, all adjustments (consisting only of normal recurring adjustments) considered necessary for fair presentation have been included. Operating results for the three months ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . For further information, refer to the consolidated financial statements and footnotes thereto included in Item 8 of our most recent Annual Report on Form 10-K. Amounts reported in millions within this report are computed based on the amounts in thousands. As a result, the sum of the components reported in millions may not equal the total amount reported in millions due to rounding. Certain columns and rows within tables may not add due to the use of rounded numbers. Percentages presented are calculated from the underlying numbers in dollars. Revision of Emerging Markets We define Emerging Markets as the 20 countries that we believe have strong growth potential based on their economic conditions, healthcare sectors and our global capabilities. Periodically, we assess our list of Emerging Markets; effective January 1, 2019, we updated our list of Emerging Market countries. Our current list is comprised of the following countries: Argentina, Brazil, Chile, China, Colombia, Czech Republic, India, Indonesia, Malaysia, Mexico, Philippines, Poland, Russia, Saudi Arabia, Slovakia, South Africa, South Korea, Thailand, Turkey and Vietnam. We have revised prior year amounts to the current years presentation (as denoted with  throughout). The revision had an immaterial impact on prior year sales . Subsequent Events We evaluate events occurring after the date of our most recent accompanying unaudited condensed consolidated balance sheet for potential recognition or disclosure in our financial statements. On April 16, 2019, the U.S. Food and Drug Administration (FDA) ordered that all manufacturers of surgical mesh products indicated for the transvaginal repair of pelvic organ prolapse stop selling and distributing their products in the United States immediately, stemming from the FDAs 2016 reclassification of these devices to class III (high risk) devices. As a result, we recognized a subsequent event to our unaudited condensed consolidated financial statements for the three months ended March 31, 2019 and recorded approximately $25 million in total pre-tax charges primarily related to inventory, intangible asset write-offs and sales returns reserves. In addition, those items requiring disclosure (nonrecognized subsequent events) in the financial statements have been disclosed accordingly. Refer to Note I  Commitments and Contingencies for more information. Accounting Standards Implemented Since December 31, 2018 ASC Update No. 2016-02 In February 2016, the Financial Accounting Standards Board (FASB) issued ASC Update No. 2016-02, Leases ( FASB ASC Topic 842, Leases ). We adopted the standard as of January 1, 2019, using the modified retrospective approach and the transition method provided by ASC Update No. 2018-11, Leases (Topic 842): Targeted Improvements . Under this method, we applied the new leasing rules on the date of adoption and recognized the cumulative effect of initially applying the standard as an adjustment to our opening balance sheet, rather than at the earliest comparative period presented in the financial statements. Prior periods presented are in accordance with the previous lease guidance under FASB ASC Topic 840, Leases . In addition, we applied the package of practical expedients permitted under FASB ASC Topic 842 transition guidance to our entire lease portfolio at January 1, 2019. As a result, we were not required to reassess (i) whether any expired or existing contracts are or contain leases, (ii) the classification of any expired or existing leases and (iii) the treatment of initial direct costs for any existing leases. Furthermore, we elected not to separate lease and non-lease components for the majority of our leases. Instead, for all applicable classes of underlying assets, we accounted for each separate lease component and the non-lease components associated with that lease component, as a single lease component. As a result of adopting FASB ASC Topic 842 on January 1, 2019, we recognized right-of-use assets of $271 million and corresponding liabilities of $278 million for our existing operating lease portfolio on our unaudited condensed consolidated balance sheet . Operating lease right-of-use assets are presented within Other long-term assets and corresponding liabilities are presented within Other current liabilities and Other long-term liabilities on our unaudited condensed consolidated balance sheets . Finance leases are immaterial to our unaudited condensed consolidated financial statements . Refer to Note E  Borrowings and Credit Arrangements for additional information. There was no material impact to our unaudited condensed consolidated statements of operations or unaudited condensed consolidated statements of cash flows . Please refer to Note G  Leases for information regarding our lease portfolio as of March 31, 2019 as accounted for under FASB ASC Topic 842 . To meet the reporting and disclosure requirements of FASB ASC Topic 842 , we implemented a new lease administration and lease accounting system in 2018 that tracks all of our material leasing arrangements. In addition, we designed and implemented new processes and internal controls during the first quarter of 2019 to ensure the completeness and accuracy of the transition adjustment and subsequent financial reporting under FASB ASC Topic 842 . We also established monitoring controls to ensure we have appropriate mechanisms in place to identify material leases timely, particularly contracts that may contain embedded lease features.