Lincare Holdings Inc., a supplier of home oxygen equipment, has agreed to pay $526,000 to end a federal “whistleblower” lawsuit that claimed three of the company’s Massachusetts facilities overbilled Medicare, authorities said last week.

Authorities had claimed that Clearwater, Fla.-based Lincare’s facilities in Marlborough, Dudley and Leicester, Mass., overbilled between January 1999 and March 2004, U.S. Attorney Michael J. Sullivan said.