The Department of Justice has filed a lawsuit against Community Health Network, saying the central Indiana health care system submitted false claims to Medicare.

According to the lawsuit, the DOJ says the network paid physicians well above market value for referrals, and paid bonuses to physicians if they referred a certain number of patients to the hospital.

Those claims, if substantiated, mean Community Health violated federal law. The Stark Law prohibits hospitals from billing Medicare for services referred by a doctor with whom the hospital has an improper financial relationship. The federal agency says Community Health submitted claims to Medicare knowing the claims were not eligible for payment. The government wants the money repaid.

In a written statement, Community Health says the network has fully cooperated with the government’s requests. The network called the claim “meritless” and a waste of government resources. Community Health has more than 100 locations across central Indiana.