Attorney General Eric Schneiderman said Dr. David Brizer also underreported his income by at least $500,000 on his state tax returns.
The 60-year-old Brizer has pleaded not guilty in Rockland County Court to charges of tax fraud, criminal sale and possession of prescription drugs and other fraud and conspiracy counts.
He remains free on bail. He could face up to 7 years in prison.
Brizer's lawyer, Michael Bachner, declined to comment.
The indictment says the doctor sold prescriptions for oxycodone and other painkillers for up to $300 each from February 2010 to August 2012.
Medicaid investigators searched his offices in August.