An employer shall, within 30 days after a written request from the plan sponsor, furnish such information as the plan sponsor reasonably determines to be necessary to enable the plan sponsor to comply with the requirements of this part.

As soon as practicable after an employer’s complete or partial withdrawal, the plan sponsor shall—

As soon as practicable after an employer’s complete or partial withdrawal, the plan sponsor shall—

(A) notify the employer of— (i) the amount of the liability, and (ii) the schedule for liability payments, and

(B) demand payment in accordance with the schedule.

No later than 90 days after the employer receives the notice described in paragraph (1), the employer—

(A) No later than 90 days after the employer receives the notice described in paragraph (1), the employer— (i) may ask the plan sponsor to review any specific matter relating to the determination of the employer’s liability and the schedule of payments, (ii) may identify any inaccuracy in the determination of the amount of the unfunded vested benefits allocable to the employer, and (iii) may furnish any additional relevant information to the plan sponsor.

(B) After a reasonable review of any matter raised, the plan sponsor shall notify the employer of— (i) the plan sponsor’s decision, (ii) the basis for the decision, and (iii) the reason for any change in the determination of the employer’s liability or schedule of liability payments.

Except as provided in subparagraph (E), the amount of each annual payment shall be the product of—

Except as provided in subparagraph (E), the amount of each annual payment shall be the product of—

(A) (i) Except as provided in subparagraphs (B) and (D) of this paragraph and in paragraphs (4) and (5), an employer shall pay the amount determined under section 1391 of this title, adjusted if appropriate first under section 1389 of this title and then under section 1386 of this title over the period of years necessary to amortize the amount in level annual payments determined under subparagraph (C), calculated as if the first payment were made on the first day of the plan year following the plan year in which the withdrawal occurs and as if each subsequent payment were made on the first day of each subsequent plan year. Actual payment shall commence in accordance with paragraph (2). (ii) The determination of the amortization period described in clause (i) shall be based on the assumptions used for the most recent actuarial valuation for the plan.

(B) In any case in which the amortization period described in subparagraph (A) exceeds 20 years, the employer’s liability shall be limited to the first 20 annual payments determined under subparagraph (C).

(C) (i) Except as provided in subparagraph (E), the amount of each annual payment shall be the product of— (I) the average annual number of contribution base units for the period of 3 consecutive plan years, during the period of 10 consecutive plan years ending before the plan year in which the withdrawal occurs, in which the number of contribution base units for which the employer had an obligation to contribute under the plan is the highest, and (II) the highest contribution rate at which the employer had an obligation to contribute under the plan during the 10 plan years ending with the plan year in which the withdrawal occurs. For purposes of the preceding sentence, a partial withdrawal described in section 1385(a)(1) of this title shall be deemed to occur on the last day of the first year of the 3-year testing period described in section 1385(b)(1)(B)(i) of this title. (ii) (I) A plan may be amended to provide that for any plan year ending before 1986 the amount of each annual payment shall be (in lieu of the amount determined under clause (i)) the average of the required employer contributions under the plan for the period of 3 consecutive plan years (during the period of 10 consecutive plan years ending with the plan year preceding the plan year in which the withdrawal occurs) for which such required contributions were the highest. (II) Subparagraph (B) shall not apply to any plan year to which this clause applies. (III) This clause shall not apply in the case of any withdrawal described in subparagraph (D). (IV) If under a plan this clause applies to any plan year but does not apply to the next plan year, this clause shall not apply to any plan year after such next plan year. (V) For purposes of this clause, the term “required contributions” means, for any period, the amounts which the employer was obligated to contribute for such period (not taking into account any delinquent contribution for any other period). (iii) A plan may be amended to provide that for the first plan year ending on or after September 26, 1980, the number “5” shall be substituted for the number “10” each place it appears in clause (i) or clause (ii) (whichever is appropriate). If the plan is so amended, the number “5” shall be increased by one for each succeeding plan year until the number “10” is reached.

(D) In any case in which a multiemployer plan terminates by the withdrawal of every employer from the plan, or in which substantially all the employers withdraw from a plan pursuant to an agreement or arrangement to withdraw from the plan— (i) the liability of each such employer who has withdrawn shall be determined (or redetermined) under this paragraph without regard to subparagraph (B), and (ii) notwithstanding any other provision of this part, the total unfunded vested benefits of the plan shall be fully allocated among all such employers in a manner not inconsistent with regulations which shall be prescribed by the corporation. Withdrawal by an employer from a plan, during a period of 3 consecutive plan years within which substantially all the employers who have an obligation to contribute under the plan withdraw, shall be presumed to be a withdrawal pursuant to an agreement or arrangement, unless the employer proves otherwise by a preponderance of the evidence.

(E) In the case of a partial withdrawal described in section 1385(a) of this title, the amount of each annual payment shall be the product of— (i) the amount determined under subparagraph (C) (determined without regard to this subparagraph), multiplied by (ii) the fraction determined under section 1386(a)(2) of this title.

(2) Withdrawal liability shall be payable in accordance with the schedule set forth by the plan sponsor under subsection (b)(1) beginning no later than 60 days after the date of the demand notwithstanding any request for review or appeal of determinations of the amount of such liability or of the schedule.

(3) Each annual payment determined under paragraph (1)(C) shall be payable in 4 equal installments due quarterly, or at other intervals specified by plan rules. If a payment is not made when due, interest on the payment shall accrue from the due date until the date on which the payment is made.

(4) The employer shall be entitled to prepay the outstanding amount of the unpaid annual withdrawal liability payments determined under paragraph (1)(C), plus accrued interest, if any, in whole or in part, without penalty. If the prepayment is made pursuant to a withdrawal which is later determined to be part of a withdrawal described in paragraph (1)(D), the withdrawal liability of the employer shall not be limited to the amount of the prepayment.

In the event of a default, a plan sponsor may require immediate payment of the outstanding amount of an employer’s withdrawal liability, plus accrued interest on the total outstanding liability from the due date of the first payment which was not timely made. For purposes of this section, the term “default” means—

(A) the failure of an employer to make, when due, any payment under this section, if the failure is not cured within 60 days after the employer receives written notification from the plan sponsor of such failure, and

(B) any other event defined in rules adopted by the plan which indicates a substantial likelihood that an employer will be unable to pay its withdrawal liability.

(6) Except as provided in paragraph (1)(A)(ii), interest under this subsection shall be charged at rates based on prevailing market rates for comparable obligations, in accordance with regulations prescribed by the corporation.

A multiemployer plan may adopt rules for other terms and conditions for the satisfaction of an employer’s withdrawal liability if such rules—

(A) are consistent with this chapter, and

(B) are not inconsistent with regulations of the corporation.

(8) In the case of a terminated multiemployer plan, an employer’s obligation to make payments under this section ceases at the end of the plan year in which the assets of the plan (exclusive of withdrawal liability claims) are sufficient to meet all obligations of the plan, as determined by the corporation.

The prohibitions provided in section 1106(a) of this title do not apply to any action required or permitted under this part or to any arrangement relating to withdrawal liability involving the plan.

(Pub. L. 93–406, title IV, § 4219, as added Pub. L. 96–364, title I, § 104(2), Sept. 26, 1980, 94 Stat. 1236; amended Pub. L. 98–369, div. A, title V, § 558(b)(1)(B), July 18, 1984, 98 Stat. 899; Pub. L. 113–235, div. O, title II, § 201(a)(7)(B), Dec. 16, 2014, 128 Stat. 2810.)