SAMHSA’s Projects for Assistance in Transition from Homelessness (PATH) program provides services for people with serious mental illness, or co-occurring mental illness and substance use disorders, who are also are experiencing homelessness or are at risk of soon becoming homeless. The Triennial Process Evaluation uses data from 2019, 2020, and 2021 to understand the services provided by grantees. Data sources include a survey of state-level PATH administrators, interviews with key state and program staff, and PATH program data. PATH is administered by the Division of State and Community Systems Development of the Center for Mental Health Services (CMHS). The Center for Behavioral Health Services and Quality’s Office of Evaluation conducted the evaluation.