22 C.F.R. § 19.9-4
Any pension payable to a former spouse under this section or pursuant to any spousal agreement or court order shall be deducted from the annuity of the principal. (See § 19.6-4 concerning retroactive adjustments.) If the annuity of such a principal in any month is discontinued or reduced so that the net amount payable is less than the pension to the former spouse or spouses of the principal because of recall, reappointment or reinstatment in the Foreign Service or reemployment in the Government service, the principal's salary, rather than annuity, shall be reduced by the amount of the pension payment(s). Such salary reductions shall be deposited in the Treasury to the credit of the Fund. If a pension to a former spouse is discontinued for any reason except a suspension pending a determination of entitlement, the annuity of the principal shall be recomputed effective as of the date of discontinuance of the pension, and paid as if the pension to the former spouse had never been deducted.
22 C.F.R. § 19.9-4