In 2013, the Helmsley Charitable Trust’s Rural Healthcare Program funded the publication of a project to assist a South Dakota American Indian tribe with evaluating the feasibility of assuming management of healthcare services for their tribal members. From this experience, a toolkit was created to help tribes to ”638,” or negotiate for sovereign control of tribal healthcare. This resource, titled the 638 Toolkit: Considerations for Tribes Regarding Contracting or Compacting for Clinical Services from the Indian Health Service Under PL 93-638, provides an outline of key factors to consider when assessing the feasibility of transferring health funding and management to tribal leadership, and the steps to take to navigate the process.