13.	Pension Plans and Other Postretirement Benefits

The following table provides the components of net periodic benefit costs:

	Pension Benefits
	Three Months Ended
	December 30,			December 24,
	2017			2016
Interest cost	$	944		$	1,041
Expected return on plan assets		(474	)		(537	)
Amortization of net loss		921			1,300
Net periodic benefit cost	$	1,391		$	1,804

	Postretirement Benefits
	Three Months Ended
	December 30,			December 24,
	2017			2016
Interest cost	$	69		$	96
Amortization of prior service credits		(124	)		—
Amortization of net (gain)		(164	)		(97	)
Net periodic benefit cost	$	(219	)	$	(1	)

The Partnership expects to contribute approximately $10,290 to the defined benefit pension plan during fiscal 2018, of which $-0- was contributed during the three months ended December 30, 2017. The projected annual contribution requirements related to the Partnership’s postretirement health care and life insurance benefit plan for fiscal 2018 is $1,243, of which $258 was contributed during the three months ended December 30, 2017.

The Partnership contributes to multi-employer pension plans (“MEPPs”) in accordance with various collective bargaining agreements covering union employees. As one of the many participating employers in these MEPPs, the Partnership is responsible with the other participating employers for any plan underfunding. As of December 30, 2017 and September 30, 2017, the Partnership’s estimated obligation to these MEPPs was $23,389 and $23,665, respectively, as a result of its voluntary full withdrawal from certain MEPPs.