3M provides the following information in its footnotes. Based on this information (all amounts in millions), 3M's U.S. Defined Benefits Plans are. of December 31, 2019. 3M Notes to Consolidated Financial Statements as U.S. Defined Benefit Plans 2019 2018 Benefits Obligations: At beginning of year $15,948 $17,360 Service cost 251 288 Interest cost 620 563 Benefit payments (1,128) (1,034) Participant contributions Plan amendments Actuarial (gain)/loss 2,209 (1,226) Foreign currency changes Curtailments and settlements 35 (3) Acquisitions and transfers At end of year $17,935 $15,948