Trustmark maintains a noncontributory tax-qualified defined benefit pension plan titled the Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions (the Continuing Plan) to satisfy commitments made by Trustmark to associates covered through plans obtained in acquisitions.

The following table presents information regarding the net periodic benefit cost for the Continuing Plan for the periods presented ($ in thousands):

	Three Months Ended March 31,
	2019			2018
Service cost	$	53		$	69
Interest cost		90			83
Expected return on plan assets		(51	)		(57	)
Recognized net loss due to lump sum settlements		31			40
Recognized net actuarial loss		93			142
Net periodic benefit cost	$	216		$	277

For the plan year ending December 31, 2019, Trustmark’s minimum required contribution to the Continuing Plan is expected to be $160 thousand; however, Management and the Board of Directors of Trustmark will monitor the Continuing Plan throughout 2019 to determine any additional funding requirements by the plan’s measurement date, which is December 31.

Trustmark maintains a nonqualified supplemental retirement plan covering key executive officers and senior officers as well as directors who have elected to defer fees. The plan provides for retirement and/or death benefits based on a participant’s covered salary or deferred fees. Although plan benefits may be paid from Trustmark’s general assets, Trustmark has purchased life insurance contracts on the participants covered under the plan, which may be used to fund future benefit payments under the plan. The measurement date for the plan is December 31. As a result of mergers prior to 2014, Trustmark became the administrator of small nonqualified supplemental retirement plans, for which the plan benefits were frozen prior to the merger date.

The following table presents information regarding the net periodic benefit cost for Trustmark’s nonqualified supplemental retirement plans for the periods presented ($ in thousands):

	Three Months Ended March 31,
	2019		2018
Service cost	$	27	$	29
Interest cost		541		495
Amortization of prior service cost		63		63
Recognized net actuarial loss		162		226
Net periodic benefit cost	$	793	$	813