EMPLOYEE BENEFIT PLANS

Pension and Other Post-Retirement Benefits

The following tables provide the components of net pension and post-retirement expense (in millions):



	16 weeks ended
	Pension						Other post-retirement benefits
	June 16, 2018			June 17, 2017			June 16, 2018			June 17, 2017
Estimated return on plan assets	$	(34.6	)	$	(36.8	)	$	—		$	—
Service cost	16.1			15.3			0.3			0.3
Interest cost	26.4			27.1			0.2			0.3
Amortization of prior service cost	—			0.1			1.1			1.1
Amortization of net actuarial (gain) loss	(1.9		)	0.1			(0.1		)	—
Net expense	$	6.0		$	5.8		$	1.5		$	1.7

The Company contributed $5.5 million and $2.1 million to its defined benefit pension plans and post-retirement benefit plans during the 16 weeks ended June 16, 2018 and June 17, 2017, respectively. For the remainder of fiscal 2018, the Company currently anticipates contributing an additional $49.8 million to these plans.

The Company also contributes to various multiemployer pension plans based on obligations arising from most of its collective bargaining agreements. These plans provide retirement benefits to participants based on their service to contributing employers. The Company recognizes expense in connection with these plans as contributions are funded.

Defined Contribution Plans and Supplemental Retirement Plans

Many of the Company's employees are eligible to contribute a percentage of their compensation to defined contribution plans ("401(k) Plans"). Participants in the 401(k) Plans may become eligible to receive a profit-sharing allocation in the form of a discretionary Company contribution based on employee compensation. In addition, the Company may also provide matching contributions based on the amount of eligible compensation contributed by the employee. All Company contributions to the 401(k) Plans are made at the discretion of the Company's Board of Managers. Total contributions expensed for these plans were $14.0 million and $13.6 million for the 16 weeks ended June 16, 2018 and June 17, 2017, respectively.