In connection with the acquisition of Arnold, the company has a defined benefit plan covering substantially all of Arnold’s employees at its Lupfig, Switzerland location. The benefits are based on years of service and the employees’ highest average compensation during the specific period.

The unfunded liability of $3.3 million is recognized in the consolidated balance sheet as a component of other non-current liabilities at March 31, 2024. Net periodic benefit cost consists of the following for the three months ended March 31, 2024 and 2023 (in thousands):


	Three months ended March 31,
	2024		2023
Service cost	$	132	$	90
Interest cost	60		60
Expected return on plan assets	(49)		(54)
Amortization of unrecognized loss	—		(9)
Effect of curtailment	(11)		(13)
Net periodic benefit cost	$	132	$	74

During the three months ended March 31, 2024, per the terms of the pension agreement, Arnold contributed $0.1 million to the plan. For the remainder of 2024, the expected contribution to the plan will be approximately $0.4 million.

The plan assets are pooled with assets of other participating employers and are not separable; therefore, the fair values of the pension plan assets at March 31, 2024 were considered Level 3.