In 1968, Navajo Community College (now Diné College) became the first tribally chartered, postsecondary institution and launched the tribal college movement. Tribal colleges and universities (TCUs) were created (1) to provide tribal citizens with a culturally relevant education that preserves and perpetuates tribal culture and language, and (2) to meet the workforce needs of Tribal Nations. Today there are 35 accredited TCUs that continue to serve this dual mission, but they face challenges to their long-term sustainability and little research has been conducted in this area. The purpose of this study was to develop a preliminary framework that identifies and describes the key components of TCU sustainability. The framework was informed by a literature review, a review of TCU strategic plans, and interviews with leaders, board members, and faculty and staff members from five TCUs located in Arizona, New Mexico, and North Dakota. The nine-point framework that emerged can help tribal colleges to focus their time and resources so they can flourish and serve their students and communities for generations to come.