More than a dozen people in Michigan are facing charges in state and federal court in connection with a nationwide health fraud investigation that resulted in charges against 324 individuals.

State and federal prosecutors have charged more than 320 people in the largest coordinated takedown of health care fraud schemes in Justice Department history that uncovered nearly $15 billion in false claims.

Matthew Galeotti, head of the justice department’s criminal division, called the operation “the beginning of a new era of aggressive prosecution and data driven prevention” of healthcare fraud.