Across the country, states are grappling with how to comply with the U.S. Supreme Court’s recent decision in Miller v. Alabama, which held that mandatory life-without-parole sentences for juveniles violate the Eighth Amendment. Following Miller, it appears a sentencer may impose life without parole on a juvenile homicide offender only in those rare instances in which the sentencer determines, after considering the mitigating qualities of youth, that the juvenile’s crime reflects “irreparable corruption.” Courts are preparing to conduct resentencing hearings in states nationwide, and new cases where juveniles face the possibility of life in prison are entering the courts. Yet courts and scholars have not addressed a fundamental question: Who is the sentencer? Can a judge decide that a particular juvenile should die in prison or does the Constitution give juveniles the right to require that a jury make that determination? Courts and state legislatures responding to Miller have assumed that a judge can impose life without parole on a juvenile, as long as the judge has discretion to impose a less severe sentence. But viewing Miller in light of the Supreme Court’s recent Sixth Amendment jury right jurisprudence raises questions about the role of the jury in these post-Miller sentencing hearings. In particular, does an Eighth Amendment limit on a sentence operate in the same way as a statutory maximum sentence and set a ceiling that cannot be raised absent a jury finding? If so, a jury must find the facts beyond a reasonable doubt that expose a juvenile to life without parole. Understanding how the Court’s recent Sixth and Eighth Amendment cases interact has broad implications for how sentencing authority is allocated not only in serious juvenile cases but also in our justice system more widely.