28 CFR §571.54

1. (a)Inmates with a committed fine, or fine and costs may be transferred to contract community-based facilities, state institutions as boarders, or state institutions for service of federal sentences running concurrently with state sentences.
2. (b)Inmates with a committed fine, or fine and costs may be committed directly to contract community-based facilities or state institutions as boarders or may be designated to state institutions for service of federal sentences running concurrently with state sentences.
3. (c)An inmate with a committed fine, or fine and costs who is imprisoned in a contract community-based facility or state institution and desires to make application for a determination of ability to pay the committed fine, or fine and costs under 18 U.S.C. 3569 may make application directly to the U.S. Magistrate Judge.
4. (d)Upon receipt of a finding by the U.S. Magistrate Judge that the inmate is not indigent, Bureau staff shall forward a referral package to the appropriate United States Attorney for a final determination as to the inmate's ability to pay the committed fine, or fine and costs.