I test how federal criminal sentences changed after the Supreme Court decision U.S. v. Booker changed the sentencing guidelines from “mandatory” to “advisory.” Conditional on final guideline cell, results show Booker significantly reduced sentences, especially for women and defendants with a terminal high school degree, but less so for college graduates. This suggests discrimination among federal judges. When accounting for judges' control over final offense level, evidence regarding high school graduates and college graduates is unchanged, but evidence that sentences fell for women and the default group weakens substantially. This latter result suggests, perhaps, a new methodology by which judges applied offense levels and guideline‐conditional sentences post‐Booker.