Table of Contents Prior service cost (benefit) 5  —  (11) (78) Amortization of prior service (cost) benefit —  (2) 5  68  Prior service credit transferred to Arconic Corporation —  —  13  —  Net amount recognized, before tax effect $ (2,096) $ 416  $ (148) $ 82  Pension benefits Other postretirement benefits For the year ended December 31, 2020 2019 2018 2020 2019 2018 Service cost $ 12  $ 25  $ 46  $ 3  $ 7  $ 7  Interest cost 97  235  219  10  28  28  Expected return on plan assets (136) (286) (306) —  —  —  Recognized net actuarial loss 78  139  168  3  4  7  Amortization of prior service cost (benefit) —  2  3  (6) (6) (7) Settlements 76  9  96  —  —  —  Curtailments —  —  23  (2) (58) (28) Net periodic benefit cost $ 127  $ 124  $ 249  $ 8  $ (25) $ 7  Discontinued operations 20  95  100  6  (15) 12  Net amount recognized in Statement of Consolidated Operations $ 107  $ 29  $ 149  $ 2  $ (10) $ (5) (1) (2) (3) (4) (5) Pension Plan Benefit Obligations Components of Net Periodic Benefit Cost 73 At December 31, 2020, the actuarial losses impacting the benefit obligation were due to changes in discount rate, alternative interest cost method and other changes including census data, partially offset by actual asset returns in excess of expected returns. (1) At December 31, 2020, the benefit obligation, fair value of plan assets, and funded status for U.S. pension plans were $2,327, $1,361, and $(966), respectively. At December 31, 2019, the benefit obligation, fair value of plan assets, and funded status for U.S. pension plans were $5,884, $3,513, and $(2,371) respectively. (2) Pension benefits 2020 2019 The projected benefit obligation and accumulated benefit obligation for all defined benefit pension plans were as follows: Projected benefit obligation $ 2,713  $ 7,249  Accumulated benefit obligation 2,707  7,219  The aggregate projected benefit obligation and fair value of plan assets for pension plans with projected benefit obligations in excess of plan assets was as follows: Projected benefit obligation 2,364  6,064  Fair value of plan assets 1,364  3,579  The aggregate accumulated benefit obligation and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets was as follows: Accumulated benefit obligation 2,359  6,045  Fair value of plan assets 1,364  3,579  In 2020, 2019 and 2018, net periodic benefit cost for U.S. pension plans was $58, $127, and $239, respectively. (1) In 2020, 2019 and 2018, net periodic benefit cost for other postretirement benefits reflects a reduction of $1, $11, and $10, respectively, related to the recognition of the federal subsidy awarded under Medicare Part D. (2) In 2020, settlements were related to U.K. actions including lump sum benefits and the purchase of group annuity contracts as well as U.S. lump sum benefit payments. In 2019 and 2018, settlements were due to workforce reductions and the payment of lump sum benefits. (See Note  E ) (3)