The U.S. Justice Department has charged 412 people for participating in healthcare fraud and crimes related to opioid abuse at a cost to taxpayers of a staggering $1.3 billion. It is the largest healthcare fraud bust in the history of the United States, according to the department.

Among the people arrested included 120 doctors and other people who are responsible for prescribing painkillers. The statement from the Justice Department described six doctors in Michigan who ran a scheme to prescibe opioids to patients unnecessarily, and then billed Medicare for a whopping $164 million.

In another case, a fake Florida rehab clinic brought in addicts and then charged $58 million in false treatments.

“Attorney General Jeff Sessions and Department of Health and Human Services (HHS) Secretary Tom Price, M.D., announced today the largest ever health care fraud enforcement action by the Medicare Fraud Strike Force, involving 412 charged defendants across 41 federal districts, including 115 doctors, nurses and other licensed medical professionals, for their alleged participation in health care fraud schemes involving approximately $1.3 billion in false billings,” the Justice Department statement reads. “Of those charged, over 120 defendants, including doctors, were charged for their roles in prescribing and distributing opioids and other dangerous narcotics. Thirty state Medicaid Fraud Control Units also participated in today’s arrests. In addition, HHS has initiated suspension actions against 295 providers, including doctors, nurses and pharmacists.”