The following terms are defined in § 4001.2 of this chapter: Code, employer, IRS, multiemployer plan, nonforfeitable benefit, PBGC, plan, and plan year.

In addition, for purposes of this part:

Initial plan year means a merged plan's first complete plan year that begins after the effective date of the merged plan.

Initial plan year unfunded vested benefits means the unfunded vested benefits as of the close of the initial plan year, less the value as of the end of the initial plan year of all outstanding claims for withdrawal liability that can reasonably be expected to be collected from employers that had withdrawn as of the end of the initial plan year.

Merged plan means a plan that is the result of the merger of two or more multiemployer plans.

Merger means the combining of two or more multiemployer plans into one multiemployer plan.

Prior plan means the plan in which an employer participated immediately before that plan became a part of the merged plan.

Unfunded vested benefits means, as described in section 4213(c) of ERISA, the amount by which the value of nonforfeitable benefits under the plan exceeds the value of the assets of the plan.

Withdrawing employer means the employer for which withdrawal liability is being calculated under section 4201 of ERISA.

Withdrawn employer means an employer that, in a plan year before the withdrawing employer withdraws, has discontinued contributions to the plan or covered operations under the plan and whose obligation to contribute has not been assumed by a successor employer within the meaning of section 4204 of ERISA. A temporary suspension of contributions, including a suspension described in section 4218(2) of ERISA, is not considered a discontinuance of contributions.