Retirement Plans (Tables)

9 Months Ended

Sep. 28, 2014

Postretirement Benefit Plans

Net Periodic Pension and Postretirement Cost (Benefit)

For the three and nine months ended September 28, 2014 and September 29, 2013, Teradyne’s net periodic pension cost was comprised of the following:

	For the Three Months Ended						For the Nine Months Ended
	September 28, 2014			September 29, 2013			September 28, 2014			September 29, 2013
	(in thousands)
Service cost	$	761		$	871		$	2,368		$	2,557
Interest cost		3,650			3,350			11,102			10,001
Expected return on plan assets		(3,335	)		(3,664	)		(10,060	)		(10,925	)
Amortization of unrecognized prior service cost		34			41			101			123
Actuarial loss (gain)		—			—			362			(1,123	)
Total net periodic pension cost	$	1,110		$	598		$	3,873		$	633

Defined Benefit Pension Plans

Net Periodic Pension and Postretirement Cost (Benefit)

For the three and nine months ended September 28, 2014 and September 29, 2013, Teradyne’s net periodic postretirement benefit was comprised of the following:

	For the Three Months Ended						For the Nine Months Ended
	September 28, 2014			September 29, 2013			September 28, 2014			September 29, 2013
	(in thousands)
Service cost	$	15		$	19		$	44		$	56
Interest cost		84			86			252			257
Amortization of unrecognized prior service benefit		(150	)		(150	)		(449	)		(449	)
Actuarial gain		—			—			(247	)		(236	)
Total net periodic post-retirement benefit	$	(51	)	$	(45	)	$	(400	)	$	(372	)