5 U.S.C. § 8909a

(a) There is in the Treasury of the United States a Postal Service Retiree Health Benefits Fund which is administered by the Office of Personnel Management. (b) The Fund is available without fiscal year limitation for payments required under section 8906(g)(2)(A). (c) The Secretary of the Treasury shall immediately invest, in interest-bearing securities of the United States such currently available portions of the Fund as are not immediately required for payments from the Fund. Such investments shall be made in the same manner as investments for the Civil Service Retirement and Disability Fund under section 8348. (d) (1) Not later than June 30, 2026 , and by June 30 of each succeeding year, the Office shall compute, for the most recently concluded fiscal year, the amount (if any) that Government contributions required to be paid from the Fund under section 8906(g)(2)(A) exceeded the estimated net claims costs under the enrollment of the individuals described in section 8906(g)(2)(A). (2) Not later than September 30 of each year in which the Office makes a computation under paragraph (1), the United States Postal Service shall pay into the Fund the amount (if any) of the excess computed under such paragraph. (e) Any computation required under section 3654(b) of title 39 shall be based on— (1) the net present value of the future net claims costs with respect to— (A) current annuitants of the United States Postal Service as of the end of the fiscal year ending on September 30 of the relevant reporting year; and (B) current employees of the United States Postal Service who would, as of September 30 of that year— (i) be eligible to become annuitants pursuant to section 8901(3)(A)(i) or (ii); and (ii) if they were retired as of that date, meet the criteria for coverage of annuitants under section 8905(b); (2) economic and actuarial methods and assumptions consistent with the methods and assumptions used in determining the Postal surplus or supplemental liability under section 8348(h); and (3) any other methods and assumptions, including a health care cost trend rate, that the Director of the Office determines to be appropriate. (f) After consultation with the United States Postal Service, the Office shall promulgate any regulations the Office determines necessary under this subsection. (g) For purposes of this section, the term “estimated net claims costs” shall mean the difference between— (1) the sum of— (A) the estimated costs incurred by a carrier in providing health services to, paying for health services provided to, or reimbursing expenses for health services provided to, annuitants of the United States Postal Service and any other persons covered under the enrollment of such annuitants; and (B) an amount of indirect expenses reasonably allocable to the provision, payment, or reimbursement described in subparagraph (A), as determined by the Office; and (2) the amount withheld from the annuity of or paid by annuitants of the United States Postal Service under section 8906.