The goal of this guide is to provide a range of different stakeholders with information and best practices for peer support and leadership in early intervention for psychosis (EIP) services. Audiences that may find this manual to be useful include state-level administrators, clinical directors, peer and family advocates, young people, and early intervention planning committee members, as well as researchers and others with an interest in youth and peer involvement. This document includes many concrete examples of exemplary or innovative services, projects and individuals (see “spotlights”), and a comprehensive appendix of resources is offered at the end of the guide. Unlike many other U.S. peer support manuals, the aim of this guide is to provide coverage of a broad range of domains in which peers might assume leadership or advisory roles. These include program development and planning, direct service delivery (including peer support), public outreach and engagement, clinician education, and quality improvement and evaluation.