(a) General. Whenever an eligible employer that has partially withdrawn from a multiemployer plan satisfies the requirements in § 4208.4 for the reduction or waiver of its partial withdrawal liability, it may apply to the plan for abatement of its partial withdrawal liability. Applications shall identify the eligible employer, the withdrawn employer (if different), the date of withdrawal, and the basis for reduction or waiver of its withdrawal liability. Upon receiving a complete 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 partial withdrawal liability under § 4208.4. If the plan sponsor determines that the employer satisfies the requirements for abatement of its partial 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 partial withdrawal liability, the provisions of paragraphs (d) and (e) of this section shall apply.

(b) Determination of abatement. Within 60 days after an eligible employer that partially withdrew from a multiemployer plan applies for abatement in accordance with paragraph (a) of this section, the plan sponsor shall determine whether the employer satisfies the requirements for abatement of its partial withdrawal liability under § 4208.4 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 § 4208.5 of this part, 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 partial withdrawal liability under § 4208.4, then—

(1) The employer's partial withdrawal liability shall be eliminated or its annual partial withdrawal liability payments shall be reduced in accordance with § 4208.6, as applicable;

(2) The employer's liability for a subsequent withdrawal shall be determined in accordance with § 4208.7;

(3) Any bonds furnished under § 4208.5 shall be canceled and any amounts held in escrow under § 4208.5 shall be refunded to the employer; and

(4) Any withdrawal liability payments originally due and paid after the end of the plan year in which the conditions for abatement were satisfied, in excess of the amount due under this part after that date shall be credited to the remaining withdrawal liability payments, if any, owed by the employer, beginning with the first payment due after the revised payment schedule is issued pursuant to this paragraph. If the credited amount is greater than the outstanding amount of the employer's partial withdrawal liability, the amount remaining after satisfaction of the liability shall be refunded to the employer. Interest on the credited amount at the rate prescribed in part 4219, subpart C, of this chapter (relating to overdue, defaulted, and overpaid withdrawal liability) shall be added if the plan sponsor does not issue a revised payment schedule reflecting the credit or make the required refund within 60 days after receipt by the plan sponsor of a complete abatement application. Interest shall accrue from the 61st day.

(d) Effects of non-abatement. If the plan sponsor determines that the employer does not satisfy the requirements for abatement of its partial withdrawal liability under § 4208.4, then the employer shall take or cause to be taken the actions set forth in paragraphs (d)(1)-(d)(3) of this section. The rules in part 4219, subpart C, shall apply with respect to all payments required to be made under paragraphs (d)(2) and (d)(3). For this purpose, a payment required 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) Any bond or escrow furnished under § 4208.5 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) 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) The employer shall resume or continue making its partial withdrawal liability payments as they are due to the plan.

(e) Review of non-abatement determination. A plan sponsor's determinations that the employer does not satisfy the requirements for abatement under § 4208.4 and of the amount of reduction determined under § 4208.6 shall be subject to plan review under section 4219(b)(2) of ERISA and to arbitration under section 4221 of ERISA and part 4221 of this chapter, within the times prescribed by those provisions. 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. If the plan sponsor upon review or an arbitrator determines that the employer satisfies the requirements for abatement of its partial withdrawal liability under § 4208.4, the plan sponsor shall immediately refund the amounts described in paragraph (e)(1) of this section if the liability is waived, or credit and refund the amounts described in paragraph (e)(2) if the annual payment is reduced.

(1) Refund for waived liability. If the employer's partial withdrawal liability is waived, the plan sponsor shall refund to the employer the payments made pursuant to paragraphs (d)(1)-(d)(3) of this section (plus interest determined in accordance with § 4219.31(d) of this chapter as if the payments were overpayments of withdrawal liability).

(2) Credit for reduced annual payment. If the employer's annual partial withdrawal liability payment is reduced, the plan sponsor shall credit the payments made pursuant to paragraphs (d)(1)-(d)(3) of this section (plus interest determined in accordance with § 4219.31(d) of this chapter as if the payments were overpayments of withdrawal liability) to future withdrawal liability payments owed by the employer, beginning with the first payment that is due after the determination, and refund any credit (including interest) remaining after satisfaction of the outstanding amount of the employer's partial withdrawal liability.