GTN Adjustments We recognize revenue net of GTN adjustments that are further described in “—Critical Accounting Policies.” The activities and ending reserve balances for each significant category of GTN adjustments were as follows: The reconciliation of gross product sales to net product sales by each significant category of GTN adjustments was as follows: GTN adjustments are primarily a function of product sales volume, regional and payer channel mix, contractual or legislative discounts and rebates. GTN adjustment percentage as a result of competitive pressures to maintain its position on healthcare payer formularies allowing patients continued access through their medical plans. GTN adjustments are increasing at a higher rate than gross product sales due to higher U.S.  Eliquis  gross product sales, which has a relatively high 34 Dollars in Millions Charge-Backs and Cash Discounts Medicaid and Medicare Rebates Other Rebates, Returns, Discounts and Adjustments Total Balance at January 1, 2017 $ 126 $ 520 $ 1,160 $ 1,806 Provision related to sale made in: Current period 2,087 2,090 2,135 6,312 Prior period (3) (4) (64) (71) Payments and returns (2,004 ) (1,810 ) (2,107 ) (5,921 ) Foreign currency translation and other 3 — 104 107 Balance at December 31, 2017 $ 209 $ 796 $ 1,228 $ 2,233 Provision related to sale made in: Current period 2,738 3,258 2,693 8,689 Prior period (3) (33) (60) (96) Payments and returns (2,695 ) (2,960 ) (2,424 ) (8,079 ) Assets/related liabilities held-for-sale — — (28) (28) Foreign currency translation and other (4 ) — (53 ) (57 ) Balance at December 31, 2018 $ 245 $ 1,061 $ 1,356 $ 2,662 Year Ended December 31, % Change Dollars in Millions 2018 2017 2016 2018 vs. 2017 2017 vs. 2016 Gross product sales $ 30,174 $ 25,499 $ 22,364 18 % 14 % GTN Adjustments Charge-backs and cash discounts (2,735 ) (2,084 ) (1,582 ) 31 % 32 % Medicaid and Medicare rebates (3,225) (2,086) (1,382) 55% 51% Other rebates, returns, discounts and adjustments (2,633 ) (2,071 ) (1,698 ) 27 % 22 % Total GTN Adjustments (8,593) (6,241) (4,662) 38% 34% Net product sales $ 21,581 $ 19,258 $ 17,702 12 % 9 % GTN adjustments percentage 28 % 24 % 21 % 4 % 3 % U.S. 36% 31% 26% 5% 5% Non-U.S. 13 % 13 % 13 % — —