In many state criminal courts, guidelines prescribe mandatory sentencing for many defendants. However, discretion eliminated at sentencing may reappear in charging, as prosecutors adjust a defendant’s arrest charge to side-step mandatory sentencing rules. We assess the extent to which prosecutors behaviorally respond to sentencing rules and the beneficiaries from their discretion. Our context is North Carolina Superior Court, where an institutional feature of the sentencing guidelines gives us purchase on prosecutors’ behavioral response to these rules. At certain criminal history cutoffs, the guidelines discontinuously shift from discretionary to mandatory incarceration. We find that prosecutors are more likely to reduce the arresting charge in cases that would otherwise be subject to mandatory incarceration. In our setting, such charge reductions undo 40% of the mechanical increase in incarceration rates around these discontinuities. We find that defendants whose observable characteristics suggest a low risk of re-offense are more likely to receive charge reductions, suggesting prosecutors’ behavioral responses to the guidelines helps to reserve incarceration for those more likely to re-offend.