Youth justice minimum age thresholds vary widely and are garnering increased global attention. In 1984, legislation in Canada excluded all children under age 12 from its youth justice system, yet few studies have examined implementation of the statute. We interviewed 22 experts across Canada to understand how the law functions and to guide responses in Canada and other nations. We used an inductive, thematic analysis process. Experts reported that excluding children under 12 from Canada’s youth justice system has been effective in eliminating juvenile legal processing for children under 12, and promoting responses that identify and address the root causes of children’s disruptive behavior outside of the legal system. Experts noted that addressing key gaps in funding and community service provision can reduce service variation by geography, race or ethnicity, socio-economic status, and ability or disability status and can enhance youths’ success. Canada’s experience suggests that for optimal implementation, minimum age laws should be coupled with robust funding and sufficient service provision to achieve racial justice and health equity.