28 U.S.C. § 2411: Interest

In any judgment of any court rendered (whether against the United States, a collector or deputy collector of internal revenue, a former collector or deputy collector, or the personal representative in case of death) for any overpayment in respect of any internal-revenue tax, interest shall be allowed at the overpayment rate established under section 6621 of the Internal Revenue Code of 1986 upon the amount of the overpayment, from the date of the payment or collection thereof to a date preceding the date of the refund check by not more than thirty days, such date to be determined by the Commissioner of Internal Revenue. The Commissioner is authorized to tender by check payment of any such judgment, with interest as herein provided, at any time after such judgment becomes final, whether or not a claim for such payment has been duly filed, and such tender shall stop the running of interest, whether or not such refund check is accepted by the judgment creditor.