Only persons who can document their ancestry to a federally recognized Indian tribe may become a member of a Native American tribe. Each tribe is a sovereign nation and may limit membership based on blood quantum, or actual percentage of native ancestry. According to the National Congress of American Indians, there are 562 federally recognized tribes in the U.S..

Ask your parents and grandparents to determine which tribe your family descends from. Elder natives faced discrimination and assimilation, and your grandparents may be leery of discussing their Native American heritage. If they are not forthcoming with their knowledge, ask them where they and their parents lived because this will give you a hint of where to look for the information you seek.

Research your native ancestry using census records and Indian rolls to verify your genealogy. Native Americans are required to show descent from a family member registered under one of the federal Indian rolls, which were taken under law by each Indian agency between 1885 and 1940.

Document your descent from the native that was registered on the official roll. For example, if your great-grandmother was found on the Dawes Roll, you will need copies of birth, marriage, baptism or death certificates for your grandparent, parent and yourself proving the direct lineage from your great-grandmother.

Contact the enrollment office of the tribe to which you wish to apply and request the official enrollment form and other information required for enrollment. Because each tribe is individually governed, the specific requirements for enrollment will vary.

Apply for enrollment as directed by the tribal enrollment office by filling out your family tree form and including the required documentation as requested by the tribe. Once the requirements have been verified you will receive an enrollment card to prove you are a member of a Native American tribe.