Except as provided in paragraph (2), the amount of any contribution required by this section (including any required installments under paragraphs (3) and (4) of section 1083(j) of this title or under section 1085a(f) of this title) shall be paid by the employer responsible for making contributions to or under the plan.
If the employer referred to in paragraph (1) is a member of a controlled group, each member of such group shall be jointly and severally liable for payment of such contributions.
Paragraph (1) shall not apply in the case of a multiemployer plan for any plan year in which the plan is in critical status pursuant to section 1085 of this title. This paragraph shall only apply if the plan sponsor adopts a rehabilitation plan in accordance with section 1085(e) of this title and complies with the terms of such rehabilitation plan (and any updates or modifications of the plan).
The Secretary of the Treasury may not waive under subparagraph (A) any portion of the minimum funding standard under subsection (a) for a plan year which is attributable to any waived funding deficiency for any preceding plan year.
For purposes of this part, the term “waived funding deficiency” means the portion of the minimum funding standard under subsection (a) (determined without regard to the waiver) for a plan year waived by the Secretary of the Treasury and not satisfied by employer contributions.
Except as provided in subparagraph (C), the Secretary of the Treasury may require an employer maintaining a defined benefit plan which is a single-employer plan (within the meaning of section 1301(a)(15) of this title) to provide security to such plan as a condition for granting or modifying a waiver under paragraph (1) or for granting an extension under section 1085a(d) of this title.
Any security provided under clause (i) may be perfected and enforced only by the Pension Benefit Guaranty Corporation, or at the direction of the Corporation, by a contributing sponsor (within the meaning of section 1301(a)(13) of this title), or a member of such sponsor’s controlled group (within the meaning of section 1301(a)(14) of this title).
The amount described in clause (i)(I) shall include any increase in such amount which would result if all applications for waivers or extensions with respect to the minimum funding standard under this subsection which are pending with respect to such plan were denied.
The term “unpaid minimum required contribution” means, with respect to any plan year, any minimum required contribution under section 1083 of this title for the plan year which is not paid on or before the due date (as determined under section 1083(j)(1) of this title) for the plan year.
For purposes of subclause (I), any payment to or under a plan for any plan year shall be allocated first to unpaid minimum required contributions for all preceding plan years on a first-in, first-out basis and then to the minimum required contribution under section 1083 of this title for the plan year.
In the case of a single-employer plan, no waiver may be granted under this subsection with respect to any plan for any plan year unless an application therefor is submitted to the Secretary of the Treasury not later than the 15th day of the 3rd month beginning after the close of such plan year.
The Secretary of the Treasury shall, before granting a waiver under this subsection, require each applicant to provide evidence satisfactory to such Secretary that the applicant has provided notice of the filing of the application for such waiver to each affected party (as defined in section 1301(a)(21) of this title). Such notice shall include a description of the extent to which the plan is funded for benefits which are guaranteed under subchapter III and for benefit liabilities.
No amendment of a plan which increases the liabilities of the plan by reason of any increase in benefits, any change in the accrual of benefits, or any change in the rate at which benefits become nonforfeitable under the plan shall be adopted if a waiver under this subsection or an extension of time under section 1084(d) of this title or section 1085a(d) of this title is in effect with respect to the plan, or if a plan amendment described in subsection (d)(2) which reduces the accrued benefit of any participant has been made at any time in the preceding 12 months (24 months in the case of a multiemployer plan). If a plan is amended in violation of the preceding sentence, any such waiver, or extension of time, shall not apply to any plan year ending on or after the date on which such amendment is adopted.
For corresponding duties of the Secretary of the Treasury with regard to implementation of title 26, see section 412(c) of title 26.
For purposes of this section, the term “controlled group” means any group treated as a single employer under subsection (b), (c), (m), or (o) of section 414 of title 26.