The Indian Health Service (IHS) remains largely misunderstood by those not directly connected to it, and often derided as a bureaucratic and confusing system by those who are. IHS marks its 70th anniversary, providing care to all Native citizens. Of course, the agency’s history is also documented in the hundreds of treaties over almost 200 years in which the U.S. Government explicitly signed on to its responsibility. We’ll trace the history of IHS from the first immunizations to Public Law 638, and chart its future amid a major reassessment of federal government services.