RETIREMENT BENEFITS

The net periodic benefit cost/(credit) of defined benefit pension plans includes:



	Three Months Ended September 30,						Nine Months Ended September 30,
Dollars in Millions	2018			2017			2018			2017
Service cost – benefits earned during the year	$	6		$	7		$	20		$	19
Interest cost on projected benefit obligation	50			48			146			142
Expected return on plan assets	(97		)	(104		)	(315		)	(308		)
Amortization of prior service credits	(1		)	(1		)	(3		)	(3		)
Amortization of net actuarial loss	17			20			57			61
Curtailments and settlements	26			22			95			91
Net periodic pension benefit cost/(credit)	$	1		$	(8	)	$	—		$	2

Pension settlement charges were recognized after determining that the annual lump sum payments will likely exceed the annual interest and service costs for the primary and certain other U.S. and international pension plans. The charges included the acceleration of a portion of unrecognized actuarial losses. Non-current pension liabilities were $383 million at September 30, 2018 and $456 million at December 31, 2017. Defined contribution plan expense in the U.S. was $49 million and $134 million for the three and nine months ended September 30, 2018 and $46 million and $142 million for the three and nine months ended September 30, 2017, respectively. Comprehensive medical and group life benefits are provided for substantially all U.S. retirees electing to participate in comprehensive medical and group life plans and to a lesser extent certain benefits for non-U.S. employees. The net periodic benefit credits were not material in both periods.