18 USC 3614 - Resentencing upon failure to pay a fine or restitution

(a) Resentencing.— 
Subject to the provisions of subsection (b), if a defendant knowingly fails to pay a delinquent fine or restitution the court may resentence the defendant to any sentence which might originally have been imposed.
(b) Imprisonment.— 
The defendant may be sentenced to a term of imprisonment under subsection (a) only if the court determines that
(1) the defendant willfully refused to pay the delinquent fine or had failed to make sufficient bona fide efforts to pay the fine; or
(2) in light of the nature of the offense and the characteristics of the person, alternatives to imprisonment are not adequate to serve the purposes of punishment and deterrence.
(c) Effect of Indigency.— 
In no event shall a defendant be incarcerated under this section solely on the basis of inability to make payments because the defendant is indigent.