Before Congress enacted the Multiemployer Pension Plan Amendments Act of 1980 (“MPPAA”), “many employers were withdrawing from multiemployer plans because they could avoid withdrawal liability if the plan survived for five years after the date of their withdrawal,” and Congress was concerned “ ‘that ERISA did not adequately protect multiemployer pension plans from the adverse consequences that result when individual employers terminate their participation or withdraw.’ ”

The MPPAA was therefore enacted and was “designed ‘(1) to protect the interests of participants and beneficiaries in financially distressed multiemployer plans, and (2) to encourage the growth and maintenance of multiemployer plans in order to ensure benefit security to plan participants.’ ”

To accomplish these goals, the MPPAA “requires that a withdrawing employer pay its share of the plan’s unfunded liability,” which “insures that the financial burden will not be shifted to the remaining employers” in the fund. 

The pension fund determines whether withdrawal liability has occurred and in what amount.  A “complete withdrawal … occurs when an employer-(1) permanently ceases to have an obligation to contribute under the plan, or (2) permanently ceases all covered operations under the plan.” The amount of an employer’s withdrawal liability is the employer’s proportionate share of the unfunded vested benefits existing at the end of the plan year preceding the plan year in which the employer withdraws.

A trustee is empowered to sue a withdrawing employer for its share of the unfunded liability of the plan. If, however, the trustee does not sue, a beneficiary may sue the trustee as well as the party or parties the trustee failed to sue. Consequently, should we discover that the trustees of the merged pension plan at issue failed to sue a withdrawing employer, we would have a cause of action against the trustees and the withdrawing party.