ITG FAQ #2 Answer-Who is covered by IRC section 7873?
Individual tribal members (either self-employed or as employees working for a qualified Indian entity) and the qualified Indian entity itself are covered.
Note: Wages are exempt if paid by a qualified Indian entity to a tribal member of the tribe whose treaty right is being exercised. Also, if the individual Indian is self-employed, his or her wages are exempt only if he is a member of the Indian tribe whose right is being exercised. Wages are not exempt if paid by an entity that is not a qualified Indian entity, or to a tribal member who is not a member of the tribe whose rights are being exercised, including self-employed tribal members who are not a member of the tribe whose rights are being exercised.