(6) Full-funding limitation (A) In general For purposes of paragraph (5), the term “full-funding limitation” means the excess (if any) of— (i) the accrued liability (including normal cost) under the plan (determined under the entry age normal funding method if such accrued liability cannot be directly calculated under the funding method used for the plan), over (ii) the lesser of— (I) the fair market value of the plan’s assets, or (II) the value of such assets determined under paragraph (2). (B) Minimum amount (i) In general In no event shall the full-funding limitation determined under subparagraph (A) be less than the excess (if any) of— (I) 90 percent of the current liability of the plan (including the expected increase in current liability due to benefits accruing during the plan year), over (II) the value of the plan’s assets determined under paragraph (2). (ii) Assets For purposes of clause (i), assets shall not be reduced by any credit balance in the funding standard account. (C) Full funding limitation For purposes of this paragraph, unless otherwise provided by the plan, the accrued liability under a multiemployer plan shall not include benefits which are not nonforfeitable under the plan after the termination of the plan (taking into consideration section 411(d)(3) ). (D) Current liability For purposes of this paragraph— (i) In general The term “current liability” means all liabilities to employees and their beneficiaries under the plan. (ii) Treatment of unpredictable contingent event benefits For purposes of clause (i), any benefit contingent on an event other than— (I) age, service, compensation, death, or disability, or (II) an event which is reasonably and reliably predictable (as determined by the Secretary), shall not be taken into account until the event on which the benefit is contingent occurs. (iii) Interest rate used The rate of interest used to determine current liability under this paragraph shall be the rate of interest determined under subparagraph (E). (iv) Mortality tables (I) Commissioners’ standard table In the case of plan years beginning before the first plan year to which the first tables prescribed under subclause (II) apply, the mortality table used in determining current liability under this paragraph shall be the table prescribed by the Secretary which is based on the prevailing commissioners’ standard table (described in section 807(d)(5)(A) ) used to determine reserves for group annuity contracts issued on January 1, 1993 . (II) Secretarial authority The Secretary may by regulation prescribe for plan years beginning after December 31, 1999 , mortality tables to be used in determining current liability under this subsection. Such tables shall be based upon the actual experience of pension plans and projected trends in such experience. In prescribing such tables, the Secretary shall take into account results of available independent studies of mortality of individuals covered by pension plans. (v) Separate mortality tables for the disabled Notwithstanding clause (iv)— (I) In general The Secretary shall establish mortality tables which may be used (in lieu of the tables under clause (iv)) to determine current liability under this subsection for individuals who are entitled to benefits under the plan on account of disability. The Secretary shall establish separate tables for individuals whose disabilities occur in plan years beginning before January 1, 1995 , and for individuals whose disabilities occur in plan years beginning on or after such date. (II) Special rule for disabilities occurring after 1994 In the case of disabilities occurring in plan years beginning after December 31, 1994 , the tables under subclause (I) shall apply only with respect to individuals described in such subclause who are disabled within the meaning of title II of the Social Security Act and the regulations thereunder. (vi) Periodic review The Secretary shall periodically (at least every 5 years) review any tables in effect under this subparagraph and shall, to the extent such Secretary determines necessary, by regulation update the tables to reflect the actual experience of pension plans and projected trends in such experience. (E) Required change of interest rate For purposes of determining a plan’s current liability for purposes of this paragraph— (i) In general If any rate of interest used under the plan under subsection (b)(6) to determine cost is not within the permissible range, the plan shall establish a new rate of interest within the permissible range. (ii) Permissible range For purposes of this subparagraph— (I) In general Except as provided in subclause (II), the term “permissible range” means a rate of interest which is not more than 5 percent above, and not more than 10 percent below, the weighted average of the rates of interest on 30-year Treasury securities during the 4-year period ending on the last day before the beginning of the plan year. (II) Secretarial authority If the Secretary finds that the lowest rate of interest permissible under subclause (I) is unreasonably high, the Secretary may prescribe a lower rate of interest, except that such rate may not be less than 80 percent of the average rate determined under such subclause. (iii) Assumptions Notwithstanding paragraph (3)(A), the interest rate used under the plan shall be— (I) determined without taking into account the experience of the plan and reasonable expectations, but (II) consistent with the assumptions which reflect the purchase rates which would be used by insurance companies to satisfy the liabilities under the plan.