Arizona has become the only state in the country where members of federally recognized tribes seeking Medicaid services are exempt from work or volunteer requirements.
The Centers for Medicare and Medicaid Services, under equal protection laws, attempted last year to force work and volunteer requirements on all Native Americans collecting benefits.
But the tribes pushed back, including the second largest tribe in the country, the Navajo Nation, along with 20 other tribes in Arizona.
Lawyers for the tribes argued that the agency was ignoring the U.S. Constitution and violating decades-old treaties.
On Friday, the agency approved the work exemption for Arizona tribal members, citing the tribes' status as political entities.
That could set a precedent for federally recognized Native American Tribes in at least eight other states currently fighting the Trump administration's work requirements for Medicaid.