EMPLOYEE BENEFIT PLANS

The NuStar Pension Plan (the Pension Plan) is a qualified non-contributory defined benefit pension plan that provides eligible U.S. employees with retirement income as calculated under a cash balance formula. The NuStar Excess Pension Plan (the Excess Pension Plan) is a nonqualified deferred compensation plan that provides benefits to a select group of management or other highly compensated employees. The Pension Plan and Excess Pension Plan are collectively referred to as the Pension Plans.

We also sponsor a contributory medical benefits plan for U.S. employees that retired prior to April 1, 2014. For employees that retire on or after April 1, 2014, we provide partial reimbursement for eligible third-party health care premiums.

The components of net periodic benefit cost (income) related to our Pension Plans and other postretirement benefit plans were as follows:



	Pension Plans						Other Postretirement Benefit Plans
	2018			2017			2018			2017
	(Thousands of Dollars)
For the three months ended March 31:
Service cost	$	2,406		$	2,239		$	126		$	113
Interest cost	1,206			1,127			108			108
Expected return on assets	(1,855		)	(1,603		)	—			—
Amortization of prior service credit	(514		)	(515		)	(287		)	(286		)
Amortization of net loss	544			371			54			48
Net periodic benefit cost (income)	$	1,787		$	1,619		$	1		$	(17	)