US authorities on Thursday slapped 412 doctors, nurses and other medical professionals with fraud charges, many for overprescribing opioids, which have stoked an expanding national addiction crisis.
Attorney General Jeff Sessions announced the charges amid what he called "the deadliest drug crisis in our history."
The charges involve doctors and others accused of operating pill mills that pump heavily addictive opioids like oxycodone into the streets through illegal prescription schemes.
The charges also target people said to have bilked the government-run Medicaid and Medicare health insurance programs for services that were never delivered, including addict rehabilitation programs, and for prescribing unnecessary drugs to patients in order to overbill the government.
In all, government losses on false billings in the fraud schemes totaled $1.3 billion, the Justice Department said.
Those charged include 56 medical doctors, six of them part of a Michigan scheme that allegedly prescribed unnecessary opioids to patients and sent $164 million in false and fraudulent claims to Medicaid.
One Houston doctor pumped out 2.5 million doses of hydrocodone and other drugs illegally as addicts and organised gangs lined up at her pain clinic daily to purchase prescriptions.
And a Palm Beach, Florida rehabilitation facility allegedly charged the government $58 million while never providing the billed services to addicts.
Instead, the government said, the facility simply recruited addicts to use their names for billings by providing them gift cards, visits to strip clubs and even drugs.
Addiction on the rise
The barely controlled pumping of hundreds of millions of doses of opioids into US communities during the past decade is blamed for a sharp surge in addiction, with an estimated two million to three million people hooked on prescription painkillers or heroin, according to the American Society of Addiction Medicine.
Last year, overdose deaths surged at least 19 percent to more than 59,000, according to preliminary estimates.
Since 2007, the government has been cracking down on hospitals, clinics and medical professionals accused of bilking government insurance programmes.
More than 3,500 people have been prosecuted in cases involving an excess of $12.5 billion in losses to Medicaid and other government programmes.