supplemental liability
(9) the term “supplemental liability” means the estimated excess of— (A) the actuarial present value of all future benefits payable from the Fund under this part based on the service of participants or former participants, over (B) the sum of— (i) the actuarial present value of (I) deductions to be withheld from the future basic pay of participants pursuant to section 4071e of this title and (II) contributions for past civilian and military service; (ii) the actuarial present value of future contributions to be made pursuant to section 4071f of this title ; (iii) the Fund balance as of the date the supplemental liability is determined, to the extent that such balance is attributable— (I) to the System, or (II) to the contributions made under the Federal Employees’ Retirement Contribution Temporary Adjustment Act of 1983 ( 5 U.S.C. 8331 note); and (iv) any other appropriate amount, as determined by the Secretary of State in accordance with generally accepted actuarial practices and principles;