29 C.F.R. § 4207.3 – Abatement.

(a) General. Whenever an eligible employer that has completely withdrawn from a multiemployer plan reenters the plan, it may apply to the plan for abatement of its complete withdrawal liability. Applications shall be filed by the date of the first scheduled withdrawal liability payment falling due after the employer resumes covered operations or, if later, the fifteenth calendar day after the employer resumes covered operations. Applications shall identify the eligible employer, the withdrawn employer, if different, the date of withdrawal, and the date of resumption of covered operations. Upon receiving an application for abatement, the plan sponsor shall determine, in accordance with paragraph (b) of this section, whether the employer satisfies the requirements for abatement of its complete withdrawal liability under § 4207.5, § 4207.9, or a plan amendment which has been approved by PBGC pursuant to § 4207.10. If the plan sponsor determines that the employer satisfies the requirements for abatement of its complete withdrawal liability, the provisions of paragraph (c) of this section shall apply. If the plan sponsor determines that the employer does not satisfy the requirements for abatement of its complete withdrawal liability, the provisions of paragraphs (d) and (e) of this section shall apply.
(b) Determination of abatement. As soon as practicable after an eligible employer that completely withdrew from a multiemployer plan applies for abatement, the plan sponsor shall determine whether the employer satisfies the requirements for abatement of its complete withdrawal liability under this part and shall notify the employer in writing of its determination and of the consequences of its determination, as described in paragraphs (c) or (d) and (e) of this section, as appropriate. If a bond or escrow has been provided to the plan under § 4207.4, the plan sponsor shall send a copy of the notice to the bonding or escrow agent.
(c) Effects of abatement. If the plan sponsor determines that the employer satisfies the requirements for abatement of its complete withdrawal liability under this part, then—
1. (1) The employer shall have no obligation to make future withdrawal liability payments to the plan with respect to its complete withdrawal;
2. (2) The employer's liability for a subsequent withdrawal shall be determined in accordance with § 4207.7 or § 4207.8, as applicable;
3. (3) Any bonds furnished under § 4207.4 shall be cancelled and any amounts held in escrow under § 4207.4 shall be refunded to the employer; and
4. (4) Any withdrawal liability payments due after the reentry and made by the employer to the plan shall be refunded by the plan without interest.
(d) Effects of non-abatement. If the plan sponsor determines that the employer does not satisfy the requirements for abatement of its complete withdrawal liability under this part, then—
1. (1) The bond or escrow furnished under § 4207.4 shall be paid to the plan within 30 days after the date of the plan sponsor's notice under paragraph (b) of this section;
2. (2) The employer shall pay to the plan within 30 days after the date of the plan sponsor's notice under paragraph (b) of this section, the amount of its withdrawal liability payment or payments, with respect to which the bond or escrow was furnished, in excess of the bond or escrow;
3. (3) The employer shall resume making its withdrawal liability payments as they are due to the plan; and
4. (4) The employer shall be treated as a new employer for purposes of any future application of the withdrawal liability rules in sections 4201-4225 of title IV of ERISA with respect to its participation in the plan after its reentry into the plan, except that in plans using the “direct attribution” method (section 4211(c)(4) of ERISA), the nonforfeitable benefits attributable to service with the employer shall include nonforfeitable benefits attributable to service prior to reentry that were not nonforfeitable at that time.
(e) Collection of payments due and review of non-abatement determination. The rules in part 4219, subpart C, of this chapter (relating to overdue, defaulted, and overpaid withdrawal liability) shall apply with respect to all payments required to be made under paragraphs (d)(2) and (d)(3) of this section. For this purpose, a payment required to be made under paragraph (d)(2) shall be treated as a withdrawal liability payment due on the 30th day after the date of the plan sponsor's notice under paragraph (b) of this section.
1. (1) Review of non-abatement determination. A plan sponsor's determination that the employer does not satisfy the requirements for abatement under this part shall be subject to plan review under section 4219(b)(2) of ERISA and to arbitration under section 4221 of ERISA, within the times prescribed by those sections. For this purpose, the plan sponsor's notice under paragraph (b) of this section shall be treated as a demand under section 4219(b)(1) of ERISA.
2. (2) Determination of abatement. If the plan sponsor or an arbitrator determines that the employer satisfies the requirements for abatement of its complete withdrawal liability under this part, the plan sponsor shall immediately refund the following payments (plus interest, except as indicated below, determined in accordance with § 4219.31(d) of this chapter as if the payments were overpayments of withdrawal liability) to the employer in a lump sum:
  1. (i) The amount of the employer's withdrawal liability payment or payments, without interest, due after its reentry and made by the employer.
  2. (ii) The bond or escrow paid to the plan under paragraph (d)(1) of this section.
  3. (iii) The amount of the employer's withdrawal liability payment or payments in excess of the bond or escrow, paid to the plan under paragraph (d)(2) of this section.
  4. (iv) Any withdrawal liability payment made by the employer to the plan pursuant to paragraph (d)(3) of this section after the plan sponsor's notice under paragraph (b) of this section.