POSTRETIREMENT PLANS

Our pretax net periodic benefit cost related to our qualified defined benefit pension plans and retiree medical and life insurance plans consisted of the following (in millions):



	Quarters Ended						Nine Months Ended
	September 24, 2017			September 25, 2016			September 24, 2017			September 25, 2016
Qualified defined benefit pension plans
Service cost	$	205		$	208		$	615		$	615
Interest cost	452			465			1,357			1,396
Expected return on plan assets	(602		)	(667		)	(1,806		)	(2,000		)
Recognized net actuarial losses	376			340			1,129			1,019
Amortization of prior service credits	(89		)	(90		)	(265		)	(272		)
Total net periodic benefit cost	$	342		$	256		$	1,030		$	758
Retiree medical and life insurance plans
Service cost	$	5		$	6		$	15		$	18
Interest cost	25			30			76			89
Expected return on plan assets	(31		)	(34		)	(95		)	(103		)
Recognized net actuarial losses	4			8			14			25
Amortization of prior service costs	4			5			11			16
Total net periodic benefit cost	$	7		$	15		$	21		$	45

The recognized net actuarial losses and amortization of net prior service (credits) costs in the table above, along with similar amounts related to our other postretirement benefit plans and 2016 IS&GS reclassifications to discontinued operations ($14 million and $41 million during the quarter and nine months ended September 24, 2017 and $8 million and $18 million for the quarter and nine months ended September 25, 2016), were reclassified from accumulated other comprehensive loss (AOCL) and recorded as a component of net periodic benefit cost for the periods presented. These costs totaled $309 million ($200 million, net of tax) and $930 million ($602 million, net of tax) during the quarter and nine months ended September 24, 2017 and $271 million ($175 million, net of tax) and $806 million ($521 million, net of tax) during the quarter and nine months ended September 25, 2016, which were recorded on our consolidated statements of comprehensive income as an increase to other comprehensive income.

The funding of our qualified defined benefit pension plans is determined in accordance with the Employee Retirement Income Security Act of 1974 (ERISA), as amended by the Pension Protection Act of 2006 (PPA), and in a manner consistent with CAS and Internal Revenue Code rules. There were no material contributions to our qualified defined benefit pension plans during the quarters and nine months ended September 24, 2017 and September 25, 2016. Currently, we do not plan to make material contributions to our pension plans in 2017, because none are required using current assumptions, including anticipated investment returns on plan assets.