Indigenous populations in the U.S. and Pacific Islands are underrepresented in mental health and substance abuse research, are underserved, and have limited access to mainstream providers. Often, they receive care that is low quality and culturally inappropriate, resulting in compromised service outcomes. The First Nations Behavioral Health Association (U.S.) and the Pacific Substance Abuse and Mental Health Collaborating Council (Pacific Jurisdictions), have developed a Compendium of Best Practices for American Indian/Alaska Native and Pacific Island Populations. The private and public sector's increasing reliance on evidence-based practices (EBP) leaves many Indigenous communities at a disadvantage. For example, funding sources may require the use of EBP without awareness of its cultural usefulness to the local Indigenous population. Indigenous communities are then faced with having to select an EBP that is rooted in non-native social and cultural contexts with no known effectiveness in an Indigenous community. The field of cultural competence has tried to influence mainstream research, and the escalating requirement of EBP use. These efforts have given rise to the practice-based evidence (PBE) and the community-defined evidence (CDE) fields. All of these efforts, ranging from evidence-based practice to community-defined evidence, have a shared goal: practice improvement.