Three people were convicted Monday in a scheme to bilk California’s Medi-Cal system out of nearly $20 million by submitting phony claims for drug and alcohol treatment for school students, federal prosecutors said.

They were the latest among 19 people convicted of federal charges involving a Long Beach-based non-profit called Atlantic Recovery Services, later called Atlantic Health Services. The organization provided treatment for substance abuse to students at local high school and middle schools, a U.S. Department of Justice statement said.

For four years ending in 2013, the organization enrolled students in its program even if they had only used drugs or alcohol once, then falsified documents to show they had a “medically diagnosed substance use disorder,” according to the statement.

Employees also submitted fraudulent documents and forged students’ signatures to falsely show they had attended counseling sessions, then billed the state’s Medi-Cal drug program for reimbursement, prosecutors said.

About $18.5 million in phony claims were submitted and the Medi-Cal program paid about $17.6 million, prosecutors said.

Atlantic’s former president and CEO, Richard Ciampa, 68, of Commerce, pleaded guilty to federal charges and was sentenced in September to seven years in prison.

The organization’s former billing supervisor, Gregory Hearns, 66, of Compton, was convicted of one count of health care fraud on Monday and acquitted of 10 other counts. Two other employees were convicted of a total of seven counts.

Each faces up to 10 years in prison for each count when they are sentenced in July.

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