Employee Retirement Plans

The components of net pension and postretirement benefits costs are summarized in the following table:



	Three months ended June 30,						Six months ended June 30,
(millions)	2014			2013			2014			2013
Pension:
Service cost of benefits earned	$	9		$	9		$	18		$	19
Interest cost on projected benefit obligation	17			16			33			31
Expected return on plan assets	(20		)	(19		)	(40		)	(38		)
Net amortization	6			12			12			23
Net pension cost	$	12		$	18		$	23		$	35
Postretirement:
Service cost of benefits earned	$	—		$	1		$	1		$	2
Interest cost on projected benefit obligation	2			2			4			3
Net amortization	(9		)	(9		)	(18		)	(17		)
Net postretirement benefit	$	(7	)	$	(6	)	$	(13	)	$	(12	)

During the first six months of 2014, we made cash contributions of $8 million to our pension plan in Canada. On July 18, 2014, we contributed $50 million in cash to the USG Corporation Retirement Plan Trust. We expect to make total contributions to our pension plans in 2014 of approximately $61 million.

In April 2014, we amended our U.S. postretirement benefit plan for those retiree medical plan participants who are pre-65 retirees, to defer the effective date that requires participants to begin purchasing individual coverage in the Affordable Insurance Exchanges or individual Medicare marketplace using a company-funded subsidy from January 1, 2015 to January 1, 2016. The financial statement impact of the plan amendment was immaterial.