28 C.F.R. § 522.13 – Relationship between existing civil contempt commitment orders and new criminal sentences imposed under the U.S. or D.C. Code.

(a) Except as stated in (b), if a civil contempt commitment order is in effect when a criminal sentence of imprisonment is imposed under the U.S. or D.C. Code, the criminal sentence runs consecutively to the commitment order, unless the sentencing judge orders otherwise.
(b) For federal criminal sentences imposed for offenses committed before November 1, 1987, under 18 U.S.C. Chapter 227: If a civil contempt commitment order is in effect when a criminal sentence of imprisonment is imposed, the criminal sentence runs concurrent with the commitment order, unless the sentencing judge orders otherwise.