Twenty-five Southern California doctors and others are accused of billing Medicare and other health plans for $150 million in fraudulent charges.
Federal cases were announced Wednesday in Los Angeles and Santa Ana.
Authorities say the defendants billed Medicare, Medicaid, private insurers and union health plans for tests, prescriptions and services that were unnecessary or were never actually provided.
More than a dozen of those charged are doctors or other medical professionals, including chiropractors and a pharmacist.