The net periodic benefit cost/(credit) of defined benefit pension plans includes: Year Ended December 31, Dollars in Millions 2019 2018 2017 Service cost — benefits earned during the year $ 26 $ 26 $ 25 Interest cost on projected benefit obligation 115 193 188 Expected return on plan assets (200 ) (386 ) (411 ) Amortization of prior service credits (4) (4) (4) Amortization of net actuarial loss 59 74 82 Settlements and Curtailments 1,640 121 159 Special termination benefits — — 3 Net periodic pension benefit cost/(credit) $ 1,636 $ 24 $ 42 Year Ended December 31, Dollars in Millions 2019 2018 Benefit obligations at beginning of year $ 5,966 $ 6,749 Service cost—benefits earned during the year 26 26 Interest cost 115 193 Settlements and Curtailments (4,105) (278) Actuarial losses/(gains) 777 (523 ) Benefits paid (109) (123) Acquisition/Divestiture 262 — Foreign currency and other 8 (78) Benefit obligations at end of year $ 2,940 $ 5,966 Fair value of plan assets at beginning of year $ 6,129 $ 6,749 Actual return on plan assets 804 (203) Employer contributions 63 71 Settlements (4,104) (276) Benefits paid (109 ) (123 ) Asset transfer (424) — Acquisition/Divestiture 164 — Foreign currency and other 13 (89) Fair value of plan assets at end of year $ 2,536 $ 6,129 (Unfunded)/Funded status $ (404 ) $ 163 Assets/(Liabilities) recognized: Other non-current assets $ 192 $ 622 Other current liabilities (27 ) (32 ) Other non-current liabilities (569) (427) Funded status $ (404 ) $ 163 Recognized in Accumulated other comprehensive loss: Net actuarial losses $ 1,192 $ 2,717 Prior service credit (26 ) (30 ) Total $ 1,166 $ 2,687 The accumulated benefit obligation for defined benefit pension plans was $2.9 billion and $6.0 billion at December 31, 2019 and 2018, respectively. 95 Pension settlement charges were recognized after determining the annual lump sum payments will exceed the annual interest and service costs for certain pension plans, including the primary U.S. pension plan in 2019, 2018 and 2017. Changes in defined benefit pension plan obligations, assets, funded status and amounts recognized in the consolidated balance sheets were as follows: