Increasingly, jurisdictions across the United States are using risk assessment instruments to scaffold efforts to unwind mass incarceration without compromising public safety. Despite promising results, critics oppose the use of these instruments to inform sentencing and correctional decisions. One argument is that the use of instruments that include gender as a risk factor will discriminate against men in sanctioning. On the basis of a sample of 14,310 federal offenders, we empirically test the predictive fairness of an instrument that omits gender, the Post Conviction Risk Assessment (PCRA). We found that the PCRA strongly predicts arrests for both genders, but overestimates women’s likelihood of recidivism. For a given PCRA score, the predicted probability of arrest, which is based on combining both genders, is too high for women. Although gender neutrality is an obviously appealing concept, it may translate into instrument bias and overly harsh sanctions for women. With respect to the moral question of disparate impact, we found that women obtain slightly lower mean scores on the PCRA than men (d = .32, 99% CI = .29−.35, or 87% overlap in scores); this difference is wholly attributable to men’s greater criminal history, a factor already embedded in sentencing guidelines.