11. Retirement Plans

Components of net periodic pension cost consisted of the following:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2018			2017			2018			2017
	(In millions)
Service cost	$	10		$	13		$	34		$	41
Interest cost		24			25			71			77
Expected return on plan assets		(49	)		(42	)		(147	)		(125	)
Amortization of unrecognized net actuarial losses		8			13			29			46
Curtailment gains		—			—			(2	)		—
Settlement loss		—			4			—			11
Pension (income) expense	$	(7	)	$	13		$	(15	)	$	50

In the first quarter of 2018, we recorded curtailment gains of $18 million to Accumulated other comprehensive income (loss) and $2 million to the Statement of Consolidated Income following workforce reductions. In connection with this curtailment, as required under accounting standards, we remeasured our U.S. retirement plans and recorded a total decrease of $125 million in the Corporation’s U.S. post retirement liabilities. This reduction was primarily driven by a change in weighted average discount rates used to measure the liabilities. There was no change to the weighted average expected long-term rate of return on plan assets.

For the full year 2018, we forecast pension service costs of approximately $45 million and net non-service pension costs of approximately $60 million of income, which is comprised of interest cost of approximately $95 million, amortization of unrecognized net actuarial losses of approximately $40 million and estimated expected return on plan assets of approximately $195 million.

Net non-service pension costs included in Other, net in the Statement of Consolidated Income for the three and nine months ended September 30, 2018 was income of $17 million and $49 million, respectively, compared to expenses of $0 million and $9 million for the three and nine months ended September 30, 2017, respectively.

In 2018, we expect to contribute $47 million to our funded pension plans. In the nine months ended September 30, 2018, we have contributed $35 million to these plans.