WASHINGTON – A federal strike force has charged 91 people, including a hospital president, doctors and nurses, with Medicare fraud schemes in seven cities involving $429 million in false billings.

At a news conference Thursday, Attorney General Eric Holder said the case reveals an alarming trend in criminal efforts to steal billions of taxpayer dollars for personal gain. Holder called the action one of the largest such law enforcement efforts of its kind.

Health and Human Services Secretary Kathleen Sebelius said that in addition to the newly announced criminal charges, her agency used new authority under the Obama administration’s health care law to stop future payments to many of the health care providers suspected of fraud. The law enforcement effort focused on fraudulent Medicare schemes in Baton Rouge, La.; Brooklyn, N.Y.; Chicago; Dallas; Houston; Los Angeles; and Miami.