Under the Medicaid Act, states received federal funds so long as they met certain requirements, including that they set medical rates that were “consistent with efficiency, economy, and quality of care” and “were sufficient to enlist enough providers” so that sufficient care and services were available in a state. The sole remedy against a state’s failure to meet the act’s requirements was the federal Department of Health and Human Services (HHS) withholding Medicaid funding. In Idaho, the state Department of Health and Welfare (DHW) (defendant) administered Medicaid. Exceptional Child Care (Exceptional) and other medical service providers (plaintiffs) sued DHW in the United States District Court for the District of Idaho, claiming that Idaho’s medical rates were lower than what the act required. The district court granted Exceptional summary judgment. The United States Court of Appeals for the Ninth Circuit affirmed. The United States Supreme Court granted certiorari.