According to the indictment, the equipment companies encouraged patients to use telemedicine doctors for maximum efficiency. “The telemedicine doctors did not have a relationship with the Medicare patients and could not physically examine them,” the indictment said.

More than 100 equipment companies will have their Medicare payments cut off as part of the operation, according to the release.

At a news conference today in Columbia, South Carolina, officials said the operation took down every aspect of the far-reaching scheme—from the international call centers to the telemarketing companies to the shipping companies that were involved.

Investigators estimate Medicare paid as much as $17 to $22 million a week to the companies allegedly participating in fraudulent practices.

“Alleged fraud like this takes money away that could be put into research or better care for patients. That billion dollars could’ve been spent on medical care for patients who really needed it,” said Special Agent Karen Corbett, an FBI Criminal Investigative Division supervisor who oversaw the case.

The massive, months-long investigation known as Operation Brace Yourself spanned 20 FBI field offices and involved several partner agencies, including the Internal Revenue Service’s Office of the Inspector General, the Department of Health and Human Services’ Office of the Inspector General, Center for Medicare and Medicaid Services, U.S. Secret Service, and the Department of Veterans’ Affairs.