M. Pension and Other Postretirement Benefits

The components of net periodic benefit cost were as follows:


	Third quarter ended September 30,						Nine months ended September 30,
Pension benefits	2017			2016			2017			2016
Service cost	$	22		$	43		$	67		$	124
Interest cost		59			114			175			358
Expected return on plan assets		(82	)		(187	)		(248	)		(558	)
Recognized net actuarial loss		55			104			165			308
Amortization of prior service cost (benefits)		1			4			4			12
Settlements		—			13			—			15
Special termination benefits		—			—			—			1

Net periodic benefit cost*	$	55		$	91		$	163		$	260
Discontinued operations		—			41			—			114

Net amount recognized in Statement of Consolidated Operations	$	55		$	50		$	163		$	146

Other postretirement benefits
Service cost	$	2		$	3		$	6		$	10
Interest cost		7			16			22			53
Recognized net actuarial loss		2			8			4			19
Amortization of prior service cost (benefits)		(2	)		(6	)		(6	)		(19	)
Special termination benefits		—			—			—			—

Net periodic benefit cost*	$	9		$	21		$	26		$	63
Discontinued operations		—			12			—			37

Net amount recognized in Statement of Consolidated Operations	$	9		$	9		$	26		$	26

Components of Net periodic benefit cost were included within Cost of goods sold, Selling, general administrative, and other expenses, Research and development expenses as well as Restructuring and other charges in the Statement of Consolidated Operations.

In conjunction with the Separation Transaction, the Pension Benefit Guaranty Corporation approved management’s plan to separate the Alcoa Inc. pension plans between Arconic Inc. and Alcoa Corporation. The plan stipulates that Arconic will make cash contributions over a period of 30 months to its two largest pension plans. Payments are expected to be made in three increments of no less than $50 each ($150 total) over this 30-month period. The first payment of $50 was made on April 18, 2017.