Retirement Plans (Tables)

3 Months Ended

Apr. 01, 2018

Defined Benefit Pension Plans

Net Periodic Pension and Postretirement benefit Cost (Income)

For the three months ended April 1, 2018 and April 2, 2017, Teradyne’s net periodic pension cost was comprised of the following:

	For the Three Months Ended
	April 1, 2018						April 2, 2017
	United States			Foreign			United States			Foreign
	(in thousands)
Service cost	$	571		$	213		$	560		$	185
Interest cost		2,997			186			3,312			163
Expected return on plan assets		(3,369	)		(5	)		(3,000	)		(6	)
Amortization of prior service cost		14			—			18			—
Total net periodic pension cost	$	213		$	394		$	890		$	342

Postretirement Benefit Plans

Net Periodic Pension and Postretirement benefit Cost (Income)

For the three months ended April 1, 2018 and April 2, 2017, Teradyne’s net periodic postretirement benefit cost (income) was comprised of the following:

	For the Three Months Ended
	April 1, 2018			April 2, 2017
	(in thousands)
Service cost	$	9		$	10
Interest cost		50			50
Amortization of prior service credit		(93	)		(124	)
Special termination benefits		1,626			—
Total net periodic postretirement benefit cost (income)	$	1,592		$	(64	)