
8.	EMPLOYEE BENEFIT PLANS

The components of net periodic benefit cost (credit) related to our defined benefit plans were as follows (in millions):



	Pension Plans						Other Postretirement Benefit Plans
	2018			2017			2018			2017
Three months ended June 30:
Service cost	$	33		$	30		$	2		$	2
Interest cost	23			22			3			2
Expected return on plan assets	(41		)	(38		)	—			—
Amortization of:
Net actuarial (gain) loss	17			14			(1		)	(1		)
Prior service credit	(4		)	(5		)	(3		)	(4		)
Special charges	3			—			—			—
Net periodic benefit cost (credit)	$	31		$	23		$	1		$	(1	)

Six months ended June 30:
Service cost	$	67		$	61		$	3		$	3
Interest cost	46			43			5			5
Expected return on plan assets	(82		)	(75		)	—			—
Amortization of:
Net actuarial (gain) loss	33			27			(1		)	(2		)
Prior service credit	(9		)	(10		)	(6		)	(8		)
Special charges	5			—			—			—
Net periodic benefit cost (credit)	$	60		$	46		$	1		$	(2	)

The components of net periodic benefit cost (credit) other than the service cost component (i.e., the non-service cost components) are included in the line item other income (expense), net in the statements of income.

We contributed $16 million and $14 million, respectively, to our pension plans and $9 million and $13 million, respectively, to our other postretirement benefit plans during the six months ended June 30, 2018 and 2017.

Management has elected to increase the discretionary contributions to our pension plans by $10 million during the second half of 2018, resulting in expected contributions to our pension plans of approximately $141 million for 2018, which includes discretionary contributions of $110 million. Our anticipated contributions to our other postretirement benefit plans during 2018 have not changed from the amount previously disclosed in our financial statements for the year ended December 31, 2017.