POSTRETIREMENT BENEFIT 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
	March 25, 2018			March 26, 2017
Qualified defined benefit pension plans
Service cost	$	157		$	159
Interest cost	435			458
Expected return on plan assets	(599		)	(562		)
Recognized net actuarial losses	444			376
Amortization of prior service credits	(81		)	(86		)
Total net periodic benefit cost	$	356		$	345
Retiree medical and life insurance plans
Service cost	$	5		$	5
Interest cost	23			26
Expected return on plan assets	(34		)	(32		)
Recognized net actuarial losses	1			5
Amortization of prior service costs	4			3
Total net periodic benefit (credit) cost	$	(1	)	$	7

We record the service cost component of net periodic benefit cost as part of cost of sales and the non-service cost components of net periodic benefit cost (i.e., interest cost, expected return on plan assets, net actuarial gains or losses, and amortization of prior service cost or credits) as part of other non-operating expense, net in the consolidated statements of earnings.

The recognized net actuarial losses and amortization of prior service (credits) costs in the table above, along with similar amounts related to our other postretirement benefit plans ($14 million for both the quarters ended March 25, 2018 and March 26, 2017), 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 $382 million ($300 million, net of tax) and $312 million ($202 million, net of tax) during the quarter ended March 25, 2018 and the quarter ended March 26, 2017, 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. During the quarter ended March 25, 2018, we contributed $1.5 billion to our qualified defined benefit pension plans. There were no material contributions to our qualified defined benefit pension plans during the quarter ended March 26, 2017. We will make additional contributions of $3.5 billion to our qualified defined benefit pension plans during the remainder of 2018.