(CNN) -- Agents arrested 20 out of 42 people accused in a California Medicaid fraud ring that allegedly bilked the state out of nearly $4.6 million and put the lives of disabled children at risk, a prosecutor said.
The defendants are accused of either posing as licensed nurses or organizing a scheme to send unlicensed nurses to provide home- or school-based care to disabled patients, many of them children with cerebral palsy or other developmental disabilities, the office of the U.S. attorney for central California said in a written statement.
The long defendant's list makes the case the largest of Medicaid fraud in California, U.S. Attorney Thomas O'Brien said in the statement.
Each defendant has been charged with conspiracy to commit health care fraud and at least one count of health care fraud, according to the statement.
Some parents and patients became suspicious of the nurses when they noticed their lack of skills.
"In one case, a 'nurse' was unable to replace a tracheotomy tube that had fallen out of a young patient's neck. In another case, an impostor nurse simply fled a medical situation when she apparently was unable to provide assistance," according to the statement.
Some of the unlicensed nurses had foreign training, but never passed a U.S. qualifying nursing exam, the attorney's office said, while others had no medical training at all.
Two defendants -- Susan Bendigo and Priscilla Villabroza, the accused ringleaders -- were charged separately.
Bendigo and Villabroza instructed the workers to lie about their status and used the names of licensed nurses on documents, the indictment says.
Villabroza operated a home health agency -- the Santa Fe Springs company Medicare Plus Home Health Providers -- the indictment said. Villabroza, a registered nurse, knowingly hired unlicensed nurses and billed Medi-Cal, California's Medicaid program, for the work of licensed vocational nurses from August 2004 through 2007, the indictment alleges.
Villabroza pleaded guilty last year to five federal counts of health care fraud, the attorney's office said.
Bendigo, a registered nurse, was also director of Santa Fe Springs' Excel Plus Home Health Services, which provided nurses to home health agencies, according to the indictment.
Bendigo also was charged last year but fled the country, the statement said. Officials think she is hiding in the Philippines, said U.S. attorney's spokesman Thom Mrozek.
Villabroza is awaiting sentencing, and could be sent to prison for up to 50 years, Mrozek said.
Each of the 42 new defendants faces a statutory maximum penalty of 10 years in federal prison for each charge if convicted, according to the statement.
All About Medicaid