Health and Human Services Secretary Kathleen Sebelius was joined by Attorney General Eric Holder today to announces a national crackdown on Medicare fraud, arresting more than 100 health care providers who had been bilking Medicare for more than $450 million.

This was the fourth such fraud sweep for the Obama administration, according to news reports. Today’s effort was part of an ongoing, three-year program aimed at Medicare and Medicaid fraud, and it was the largest single one-day bust for fraud in the history of either health program.

Arrests were also made in Chicago, Los Angeles, Baton Rouge, Tampa, Miami, Houston, and Detroit.