More than 500 federally recognized Native American tribes (including Alaska natives) are present in the United States. Tribal governments and members face numerous challenges, including high poverty, unemployment, and mortality rates. One of the many factors contributing to these conditions is the lack of clear rules on the interplay between state and tribal taxing authority. Statutes, treaties, and court decisions establish that tribes may tax their members, as well as non-members that engage in transactions with the tribe, but generally may not tax other non-members (including non-Indians) who live within reservation boundaries. Limited tribal taxing power (and capacity) make it difficult for tribes to provide adequate public services. Although states are generally preempted from taxing tribal property and the income that tribal members derive on the reservation, they may tax non-members, including those that engage in transactions with the tribe. Double taxation by state and tribal governments can occur, which “places those who deal with tribes at a disadvantage” and impedes tribal economic development.