29 C.F.R. § 4044.10

(a) General. The plan administrator shall allocate plan assets available to pay for benefits under the plan using the rules and procedures set forth in paragraphs (b) through (f) of this section, or any other procedure that results in each participant (or beneficiary) receiving the same benefits he or she would receive if the procedures in paragraphs (b) through (f) were followed.

(b) Assigning benefits. The basic-type and nonbasic-type benefits payable with respect to each participant in a terminated plan shall be assigned to one or more priority categories in accordance with §§ 4044.11 through 4044.16. Benefits derived from voluntary employee contributions, which are assigned only to priority category 1, are treated, under section 204(c)(4) of ERISA and section 411(d)(5) of the Code, as benefits under a separate plan. The amount of a benefit payable with respect to each participant shall be determined as of the termination date.

(c) Valuing benefits. The value of a participant's benefit or benefits assigned to each priority category shall be determined, as of the allocation date, in accordance with the provisions of subpart B of this part. The value of each participant's basic-type benefit or benefits in a priority category shall be reduced by the value of the participant's benefit of the same type that is assigned to a higher priority category. Except as provided in the next two sentences, the same procedure shall be followed for nonbasic-type benefits. The value of a participant's nonbasic-type benefits in priority categories 3, 5, and 6 shall not be reduced by the value of the participant's nonbasic-type benefit assigned to priority category 2. Benefits in priority category 1 shall neither be included in nor subtracted from lower priority categories. In no event shall a benefit assigned to a priority category be valued at less than zero.

(d) Allocating assets to priority categories. Plan assets available to pay for benefits under the plan shall be allocated to each priority category in succession, beginning with priority category 1. If the plan has sufficient assets to pay for all benefits in a priority category, the remaining assets shall then be allocated to the next lower priority category. This process shall be repeated until all benefits in priority categories 1 through 6 have been provided or until all available plan assets have been allocated.

(e) Allocating assets within priority categories. Except for priority category 5, if the plan assets available for allocation to any priority category are insufficient to pay for all benefits in that priority category, those assets shall be distributed among the participants according to the ratio that the value of each participant's benefit or benefits in that priority category bears to the total value of all benefits in that priority category. If the plan assets available for allocation to priority category 5 are insufficient to pay for all benefits in that category, the assets shall be allocated, first, to the value of each participant's nonforfeitable benefits that would be assigned to priority category 5 under § 4044.15 after reduction for the value of benefits assigned to higher priority categories, based only on the provisions of the plan in effect at the beginning of the 5-year period immediately preceding the termination date. If assets available for allocation to priority category 5 are sufficient to fully satisfy the value of those benefits, assets shall then be allocated to the value of the benefit increase under the oldest amendment during the 5-year period immediately preceding the termination date, reduced by the value of benefits assigned to higher priority categories (including higher subcategories in priority category 5). This allocation procedure shall be repeated for each succeeding plan amendment within the 5-year period until all plan assets available for allocation have been exhausted. If an amendment decreased benefits, amounts previously allocated with respect to each participant in excess of the value of the reduced benefit shall be reduced accordingly. In the subcategory in which assets are exhausted, the assets shall be distributed among the participants according to the ratio that the value of each participant's benefit or benefits in that subcategory bears to the total value of all benefits in that subcategory.

(f) Applying assets to basic-type or nonbasic-type benefits within priority categories. The assets allocated to a participant's benefit or benefits within each priority category shall first be applied to pay for the participant's basic-type benefit or benefits assigned to that priority category. Any assets allocated on behalf of that participant remaining after satisfying the participant's basic-type benefit or benefits in that priority category shall then be applied to pay for the participant's nonbasic-type benefit or benefits assigned to that priority category. If the assets allocable to a participant's basic-type benefit or benefits in all priority categories are insufficient to pay for all of the participant's guaranteed benefits, the assets allocated to that participant's benefit in priority category 4 shall be applied, first, to the guaranteed portion of the participant's benefit in priority category 4. The remaining assets allocated to that participant's benefit in priority category 4, if any, shall be applied to the nonguaranteed portion of the participant's benefit.

(g) Allocation to established subclasses. Notwithstanding paragraphs (e) and (f) of this section, the assets of a plan that has established subclasses within any priority category may be allocated to the plan's subclasses in accordance with the rules set forth in § 4044.17.