NOTE 13. POSTRETIREMENT BENEFIT PLANS

We sponsor a number of pension and retiree health and life insurance benefit plans. Principal pension plans are the GE Pension Plan and the GE Supplementary Pension Plan. Other pension plans include the U.S. and non-U.S. pension plans with pension assets or obligations greater than $50 million. Principal retiree benefit plans provide health and life insurance benefits to certain eligible participants and these participants share in the cost of the healthcare benefits. Smaller pension plans and other retiree benefit plans are not material individually or in the aggregate.



EFFECT ON OPERATIONS OF PENSION PLANS	Principal pension plans
	Three months ended March 31
(In millions)	2019				2018

Service cost for benefits earned	$	158			$	232
Prior service cost amortization	33				36
Expected return on plan assets	(863		)		(820		)
Interest cost on benefit obligations	726				666
Net actuarial loss amortization	763				951
Curtailment loss	51			(a)	—
Pension plans cost	$	868			$	1,065


(a)	Curtailment loss resulting from the spin-off and subsequent merger of our Transportation segment with Wabtec which is included in "Earnings (loss) from discontinued operations" in our consolidated Statement of Earnings (Loss).



	Other pension plans
	Three months ended March 31
(In millions)	2019			2018

Service cost for benefits earned	$	66		$	95
Expected return on plan assets	(309		)	(358		)
Interest cost on benefit obligations	157			156
Net actuarial loss amortization	83			82
Settlement loss	9			—
Pension plans cost (income)	$	6		$	(25	)

Principal retiree benefit plans income was $61 million and $21 million for the three months ended March 31, 2019 and 2018, respectively, which includes a curtailment gain of $33 million in 2019 resulting from the spin-off and subsequent merger of our Transportation segment with Wabtec. The curtailment gain is included in "Earnings (loss) from discontinued operations" in our consolidated Statement of Earnings (Loss). The components of net periodic benefit costs other than the service cost component are included in the caption "Non-operating benefit costs" in our consolidated Statement of Earnings (Loss).

We also have a defined contribution plan for eligible U.S. employees that provides discretionary contributions. Defined contribution plan costs were $101 million and $117 million for the three months ended March 31, 2019 and 2018, respectively.