(a) General rule
For purposes of section 401(a)(29), a defined benefit plan which is a single-employer plan (other than a CSEC plan) shall be treated as meeting the requirements of this section if the plan meets the requirements of subsections (b), (c), (d), and (e).

(b) Funding-based limitation on shutdown benefits and other unpredictable contingent event benefits under single-employer plans

(1) In general
If a participant of a defined benefit plan which is a single-employer plan is entitled to an unpredictable contingent event benefit payable with respect to any event occurring during any plan year, the plan shall provide that such benefit may not be provided if the adjusted funding target attainment percentage for such plan year—

(A) is less than 60 percent, or

(B) would be less than 60 percent taking into account such occurrence.

(2) Exemption
Paragraph (1) shall cease to apply with respect to any plan year, effective as of the first day of the plan year, upon payment by the plan sponsor of a contribution (in addition to any minimum required contribution under section 430) equal to—

(A) in the case of paragraph (1)(A), the amount of the increase in the funding target of the plan (under section 430) for the plan year attributable to the occurrence referred to in paragraph (1), and

(B) in the case of paragraph (1)(B), the amount sufficient to result in an adjusted funding target attainment percentage of 60 percent.

(3) Unpredictable contingent event benefit
For purposes of this subsection, the term "unpredictable contingent event benefit" means any benefit payable solely by reason of—

(A) a plant shutdown (or similar event, as determined by the Secretary), or

(B) an event other than the attainment of any age, performance of any service, receipt or derivation of any compensation, or occurrence of death or disability.

(c) Limitations on plan amendments increasing liability for benefits

(1) In general
No amendment to a defined benefit plan which is a single-employer plan which has the effect of increasing liabilities of the plan by reason of increases in benefits, establishment of new benefits, changing the rate of benefit accrual, or changing the rate at which benefits become nonforfeitable may take effect during any plan year if the adjusted funding target attainment percentage for such plan year is—

(A) less than 80 percent, or

(B) would be less than 80 percent taking into account such amendment.

(2) Exemption
Paragraph (1) shall cease to apply with respect to any plan year, effective as of the first day of the plan year (or if later, the effective date of the amendment), upon payment by the plan sponsor of a contribution (in addition to any minimum required contribution under section 430) equal to—

(A) in the case of paragraph (1)(A), the amount of the increase in the funding target of the plan (under section 430) for the plan year attributable to the amendment, and

(B) in the case of paragraph (1)(B), the amount sufficient to result in an adjusted funding target attainment percentage of 80 percent.

(3) Exception for certain benefit increases
Paragraph (1) shall not apply to any amendment which provides for an increase in benefits under a formula which is not based on a participant's compensation, but only if the rate of such increase is not in excess of the contemporaneous rate of increase in average wages of participants covered by the amendment.

(d) Limitations on accelerated benefit distributions

(1) Funding percentage less than 60 percent
A defined benefit plan which is a single-employer plan shall provide that, in any case in which the plan's adjusted funding target attainment percentage for a plan year is less than 60 percent, the plan may not pay any prohibited payment after the valuation date for the plan year.

(2) Bankruptcy
A defined benefit plan which is a single-employer plan shall provide that, during any period in which the plan sponsor is a debtor in a case under title 11, United States Code, or similar Federal or State law, the plan may not pay any prohibited payment. The preceding sentence shall not apply on or after the date on which the enrolled actuary of the plan certifies that the adjusted funding target attainment percentage of such plan (determined by not taking into account any adjustment of segment rates under section 430(h)(2)(C)(iv)) is not less than 100 percent.

(3) Limited payment if percentage at least 60 percent but less than 80 percent

(A) In general
A defined benefit plan which is a single-employer plan shall provide that, in any case in which the plan's adjusted funding target attainment percentage for a plan year is 60 percent or greater but less than 80 percent, the plan may not pay any prohibited payment after the valuation date for the plan year to the extent the amount of the payment exceeds the lesser of—

(i) 50 percent of the amount of the payment which could be made without regard to this section, or

(ii) the present value (determined under guidance prescribed by the Pension Benefit Guaranty Corporation, using the interest and mortality assumptions under section 417(e)) of the maximum guarantee with respect to the participant under section 4022 of the Employee Retirement Income Security Act of 1974.

(B) One-time application

(i) In general
The plan shall also provide that only 1 prohibited payment meeting the requirements of subparagraph (A) may be made with respect to any participant during any period of consecutive plan years to which the limitations under either paragraph (1) or (2) or this paragraph applies.

(ii) Treatment of beneficiaries
For purposes of this subparagraph, a participant and any beneficiary on his behalf (including an alternate payee, as defined in section 414(p)(8)) shall be treated as 1 participant. If the accrued benefit of a participant is allocated to such an alternate payee and 1 or more other persons, the amount under subparagraph (A) shall be allocated among such persons in the same manner as the accrued benefit is allocated unless the qualified domestic relations order (as defined in section 414(p)(1)(A)) provides otherwise.

(4) Exception
This subsection shall not apply to any plan for any plan year if the terms of such plan (as in effect for the period beginning on September 1, 2005, and ending with such plan year) provide for no benefit accruals with respect to any participant during such period.

(5) Prohibited payment
For purpose of this subsection, the term "prohibited payment" means—

(A) any payment, in excess of the monthly amount paid under a single life annuity (plus any social security supplements described in the last sentence of section 411(a)(9)), to a participant or beneficiary whose annuity starting date (as defined in section 417(f)(2)) occurs during any period a limitation under paragraph (1) or (2) is in effect,

(B) any payment for the purchase of an irrevocable commitment from an insurer to pay benefits, and

(C) any other payment specified by the Secretary by regulations.

Such term shall not include the payment of a benefit which under section 411(a)(11) may be immediately distributed without the consent of the participant.

(e) Limitation on benefit accruals for plans with severe funding shortfalls

(1) In general
A defined benefit plan which is a single-employer plan shall provide that, in any case in which the plan's adjusted funding target attainment percentage for a plan year is less than 60 percent, benefit accruals under the plan shall cease as of the valuation date for the plan year.

(2) Exemption
Paragraph (1) shall cease to apply with respect to any plan year, effective as of the first day of the plan year, upon payment by the plan sponsor of a contribution (in addition to any minimum required contribution under section 430) equal to the amount sufficient to result in an adjusted funding target attainment percentage of 60 percent.

(f) Rules relating to contributions required to avoid benefit limitations

(1) Security may be provided

(A) In general
For purposes of this section, the adjusted funding target attainment percentage shall be determined by treating as an asset of the plan any security provided by a plan sponsor in a form meeting the requirements of subparagraph (B).

(B) Form of security
The security required under subparagraph (A) shall consist of—

(i) a bond issued by a corporate surety company that is an acceptable surety for purposes of section 412 of the Employee Retirement Income Security Act of 1974,

(ii) cash, or United States obligations which mature in 3 years or less, held in escrow by a bank or similar financial institution, or

(iii) such other form of security as is satisfactory to the Secretary and the parties involved.

(C) Enforcement
Any security provided under subparagraph (A) may be perfected and enforced at any time after the earlier of—

(i) the date on which the plan terminates,

(ii) if there is a failure to make a payment of the minimum required contribution for any plan year beginning after the security is provided, the due date for the payment under section 430(j), or

(iii) if the adjusted funding target attainment percentage is less than 60 percent for a consecutive period of 7 years, the valuation date for the last year in the period.

(D) Release of security
The security shall be released (and any amounts thereunder shall be refunded together with any interest accrued thereon) at such time as the Secretary may prescribe in regulations, including regulations for partial releases of the security by reason of increases in the adjusted funding target attainment percentage.

(2) Prefunding balance or funding standard carryover balance may not be used
No prefunding balance or funding standard carryover balance under section 430(f) may be used under subsection (b), (c), or (e) to satisfy any payment an employer may make under any such subsection to avoid or terminate the application of any limitation under such subsection.

(3) Deemed reduction of funding balances

(A) In general
Subject to subparagraph (C), in any case in which a benefit limitation under subsection (b), (c), (d), or (e) would (but for this subparagraph and determined without regard to subsection (b)(2), (c)(2), or (e)(2)) apply to such plan for the plan year, the plan sponsor of such plan shall be treated for purposes of this title as having made an election under section 430(f) to reduce the prefunding balance or funding standard carryover balance by such amount as is necessary for such benefit limitation to not apply to the plan for such plan year.

(B) Exception for insufficient funding balances
Subparagraph (A) shall not apply with respect to a benefit limitation for any plan year if the application of subparagraph (A) would not result in the benefit limitation not applying for such plan year.

(C) Restrictions of certain rules to collectively bargained plans
With respect to any benefit limitation under subsection (b), (c), or (e), subparagraph (A) shall only apply in the case of a plan maintained pursuant to 1 or more collective bargaining agreements between employee representatives and 1 or more employers.

(g) New plans
Subsections (b), (c), and (e) shall not apply to a plan for the first 5 plan years of the plan. For purposes of this subsection, the reference in this subsection to a plan shall include a reference to any predecessor plan.

(h) Presumed underfunding for purposes of benefit limitations

(1) Presumption of continued underfunding
In any case in which a benefit limitation under subsection (b), (c), (d), or (e) has been applied to a plan with respect to the plan year preceding the current plan year, the adjusted funding target attainment percentage of the plan for the current plan year shall be presumed to be equal to the adjusted funding target attainment percentage of the plan for the preceding plan year until the enrolled actuary of the plan certifies the actual adjusted funding target attainment percentage of the plan for the current plan year.

(2) Presumption of underfunding after 10th month
In any case in which no certification of the adjusted funding target attainment percentage for the current plan year is made with respect to the plan before the first day of the 10th month of such year, for purposes of subsections (b), (c), (d), and (e), such first day shall be deemed, for purposes of such subsection, to be the valuation date of the plan for the current plan year and the plan's adjusted funding target attainment percentage shall be conclusively presumed to be less than 60 percent as of such first day.

(3) Presumption of underfunding after 4th month for nearly underfunded plans
In any case in which—

(A) a benefit limitation under subsection (b), (c), (d), or (e) did not apply to a plan with respect to the plan year preceding the current plan year, but the adjusted funding target attainment percentage of the plan for such preceding plan year was not more than 10 percentage points greater than the percentage which would have caused such subsection to apply to the plan with respect to such preceding plan year, and

(B) as of the first day of the 4th month of the current plan year, the enrolled actuary of the plan has not certified the actual adjusted funding target attainment percentage of the plan for the current plan year,

until the enrolled actuary so certifies, such first day shall be deemed, for purposes of such subsection, to be the valuation date of the plan for the current plan year and the adjusted funding target attainment percentage of the plan as of such first day shall, for purposes of such subsection, be presumed to be equal to 10 percentage points less than the adjusted funding target attainment percentage of the plan for such preceding plan year.

(i) Treatment of plan as of close of prohibited or cessation period
For purposes of applying this title—

(1) Operation of plan after period
Unless the plan provides otherwise, payments and accruals will resume effective as of the day following the close of the period for which any limitation of payment or accrual of benefits under subsection (d) or (e) applies.

(2) Treatment of affected benefits
Nothing in this subsection shall be construed as affecting the plan's treatment of benefits which would have been paid or accrued but for this section.

(j) Terms relating to funding target attainment percentage
For purposes of this section—

(1) In general
The term "funding target attainment percentage" has the same meaning given such term by section 430(d)(2).

(2) Adjusted funding target attainment percentage
The term "adjusted funding target attainment percentage" means the funding target attainment percentage which is determined under paragraph (1) by increasing each of the amounts under subparagraphs (A) and (B) of section 430(d)(2) by the aggregate amount of purchases of annuities for employees other than highly compensated employees (as defined in section 414(q)) which were made by the plan during the preceding 2 plan years.

(3) Application to plans which are fully funded without regard to reductions for funding balances
In the case of a plan for any plan year, if the funding target attainment percentage is 100 percent or more (determined without regard to the reduction in the value of assets under section 430(f)(4)), the funding target attainment percentage for purposes of paragraphs (1) and (2) shall be determined without regard to such reduction.

(k) Secretarial authority for plans with alternate valuation date
In the case of a plan which has designated a valuation date other than the first day of the plan year, the Secretary may prescribe rules for the application of this section which are necessary to reflect the alternate valuation date.

(l) Single-employer plan
For purposes of this section, the term "single-employer plan" means a plan which is not a multiemployer plan.