We conducted focus groups with high school staff, students, parents and administrators to gain information about how to design professional development training supporting high school staff in implementing restorative practices within a multi-tiered support system. Results indicated that all stakeholders valued trust and relationship building, and identified equity, accountability, and home-school communications as key elements of effective discipline approaches. We provide recommendations for designing professional development for high school staff in effectively and sustainably integrating restorative practices with existing multi-tiered student support systems. [This paper was published in "National Association of Secondary School Principals Bulletin" v105 n4 p250-275 2021 (EJ1320567).]