In a recent series of cases, the US Supreme Court has recognized that “children are different” from adults, concluding that these differences must inform how we treat children accused of serious crimes. If “children are different” when they are charged with homicide and face a possible sentence of life without parole, they are also “different” when they are charged with sex offenses and face the possibility of mandatory lifetime sex-offender registration. The same principles that have led the Court to categorically exempt youths from the death penalty, life without parole for nonhomicide crimes, and mandatory life-without-parole sentences should lead to the abolition of mandatory lifetime juvenile-sex-offender registration. This Essay argues that the Court’s reasoning and analysis in recent juvenile-justice cases indicate that mandatory lifetime juvenile-sex-offender registration is ripe for successful challenge.