(4) Liquidity requirement in connection with quarterly contributions (A) In general A plan to which this paragraph applies shall be treated as failing to pay the full amount of any required installment under paragraph (3) to the extent that the value of the liquid assets paid in such installment is less than the liquidity shortfall (whether or not such liquidity shortfall exceeds the amount of such installment required to be paid but for this paragraph). (B) Plans to which paragraph applies This paragraph shall apply to a plan (other than a plan described in subsection (g)(2)(B)) which— (i) is required to pay installments under paragraph (3) for a plan year, and (ii) has a liquidity shortfall for any quarter during such plan year. (C) Period of underpayment For purposes of paragraph (3)(A), any portion of an installment that is treated as not paid under subparagraph (A) shall continue to be treated as unpaid until the close of the quarter in which the due date for such installment occurs. (D) Limitation on increase If the amount of any required installment is increased by reason of subparagraph (A), in no event shall such increase exceed the amount which, when added to prior installments for the plan year, is necessary to increase the funding target attainment percentage of the plan for the plan year (taking into account the expected increase in funding target due to benefits accruing or earned during the plan year) to 100 percent. (E) Definitions For purposes of this paragraph— (i) Liquidity shortfall The term “liquidity shortfall” means, with respect to any required installment, an amount equal to the excess (as of the last day of the quarter for which such installment is made) of— (I) the base amount with respect to such quarter, over (II) the value (as of such last day) of the plan’s liquid assets. (ii) Base amount (I) In general The term “base amount” means, with respect to any quarter, an amount equal to 3 times the sum of the adjusted disbursements from the plan for the 12 months ending on the last day of such quarter. (II) Special rule If the amount determined under subclause (I) exceeds an amount equal to 2 times the sum of the adjusted disbursements from the plan for the 36 months ending on the last day of the quarter and an enrolled actuary certifies to the satisfaction of the Secretary of the Treasury that such excess is the result of nonrecurring circumstances, the base amount with respect to such quarter shall be determined without regard to amounts related to those nonrecurring circumstances. (iii) Disbursements from the plan The term “disbursements from the plan” means all disbursements from the trust, including purchases of annuities, payments of single sums and other benefits, and administrative expenses. (iv) Adjusted disbursements The term “adjusted disbursements” means disbursements from the plan reduced by the product of— (I) the plan’s funding target attainment percentage for the plan year, and (II) the sum of the purchases of annuities, payments of single sums, and such other disbursements as the Secretary of the Treasury shall provide in regulations. (v) Liquid assets The term “liquid assets” means cash, marketable securities, and such other assets as specified by the Secretary of the Treasury in regulations. (vi) Quarter The term “quarter” means, with respect to any required installment, the 3-month period preceding the month in which the due date for such installment occurs. (F) Regulations The Secretary of the Treasury may prescribe such regulations as are necessary to carry out this paragraph.