Owners and employees of several Los Angeles-area businesses were convicted this week of operating Medicare fraud schemes that took in about $7 million in false billing.

Yaroslav Proshak, the former owner-operator of Gardena ambulance firm ProMed Medical Transportation, and two managers of the firm, Emilia Zverev and Sharetta Michelle Wallace, were convicted Tuesday of health care fraud and conspiracy.

ProMed provided non-emergency ambulance transportation services to Medicare beneficiaries, including many dialysis patients. The government found that over two years, the defendants conspired to bill Medicare for ambulance transportation services for people they knew did not need it.

The defendants instructed emergency medical technicians working at ProMed to conceal the true medical conditions of patients they were transporting by altering paperwork and creating fraudulent documents to justify the transportation services, according to federal prosecutors.

ProMed submitted at least $2.4 million in false and fraudulent claims to Medicare for medically unnecessary transportation services. Medicare paid at least $1.2 million of those claims.

The defendants will be sentenced in November.

Separately, Hovik Simitian, who owned and operated three East Hollywood clinics – Columbia Medical Group Inc., Life Care Medical Clinic and Safe Health Medical Clinic – pleaded guilty Tuesday to conspiracy to commit health care fraud.

He admitted that over four years, he and co-conspirators paid cash kickbacks to patient recruiters who brought Medicare beneficiaries to the clinics and billed Medicare for lab tests and other services that either were not medically necessary or never happened.

Simitian further admitted that he and his co-conspirators submitted about $4.5 million in fraudulent claims to Medicare, of which the government agency paid about $1.7 million. Simitian is also scheduled to be sentenced in November.

Both cases were brought as part of the Medicare Fraud Strike Force, supervised by the Criminal Division’s Fraud Section and the United States Attorney’s Office for the Central District of California.

The Affordable Care Act has provided an additional $350 million for health care fraud prevention and enforcement, allowing the Justice Department to hire more prosecutors and expand its Medicare Fraud Strike Force, jointly run with the Department of Health and Human Services.