Retirement Plans (Tables)

9 Months Ended

Sep. 29, 2019

Defined Benefit Pension Plans

Net Periodic Pension and Postretirement Benefit Costs

For the three and nine months ended September 29, 2019 and September 30, 2018, Teradyne’s net periodic pension cost was comprised of the following:

	For the Three Months Ended
	September 29, 2019						September 30, 2018
	United States			Foreign			United States			Foreign
	(in thousands)
Service cost	$	402		$	183		$	538		$	203
Interest cost		1,797			168			1,750			177
Expected return on plan assets		(1,510	)		(7	)		(1,551	)		(5	)
Amortization of prior service cost		—			—			14			—
Settlement loss		—			—			267			—
Total net periodic pension cost	$	689		$	344		$	1,018		$	375

	For the Nine Months Ended
	September 29, 2019						September 30, 2018
	United States			Foreign			United States			Foreign
	(in thousands)
Service cost	$	1,206		$	550		$	1,657		$	609
Interest cost		5,392			505			7,188			532
Expected return on plan assets		(4,531	)		(21	)		(7,484	)		(15	)
Amortization of prior service cost		—			—			43			—
Net actuarial loss (gain)		252			—			(189	)		—
Settlement loss		—			—			345			—
Total net periodic pension cost	$	2,319		$	1,034		$	1,560		$	1,126

Postretirement Benefit Plans

Net Periodic Pension and Postretirement Benefit Costs

For the three and nine months ended September 29, 2019 and September 30, 2018, Teradyne’s net periodic postretirement benefit cost was comprised of the following:

	For the Three Months Ended						For the Nine Months Ended
	September 29, 2019			September 30, 2018			September 29, 2019			September 30, 2018
	(in thousands)
Service cost	$	10		$	10		$	31		$	29
Interest cost		87			49			260			147
Amortization of prior service credit		(48	)		(93	)		(143	)		(280	)
Net actuarial loss		—			—			196			40
Special termination benefits		—			601			—			3,419
Total net periodic postretirement benefit cost	$	49		$	567		$	344		$	3,355