A Certificate of Degree of Indian Blood or Certificate of Degree of Alaska Native Blood is an official U.S. document that certifies an individual possesses a specific fraction of Native American ancestry of a federally recognized Indian tribe, band, nation, pueblo, village, or community. They are issued by the Bureau of Indian Affairs after the applicant supplies a completed genealogy with supporting legal documents such as birth certificates, showing their descent, through one or both birth parents, from an enrolled Indian or an Indian listed in a base roll such as the Dawes Rolls. Blood degree cannot be obtained through adoptive parents. The blood degree on previously issued CDIBs or on the base rolls in the filer's ancestry are used to determine the filer's blood degree. Information collected for the filing is held confidential by privacy laws, except if the CDIB is related to assigned duties.