About 3,700 retirees were notified last week that their fee-for-service Medicare plan known as North Star Advantage would be cancelled. NorthStar was launched in 2007 by Metropolitan Health Plan of Minneapolis, which is owned by Hennepin County. The Hennepin County Board decided to end the plan—primarily because fewer doctors will accept fee-for-service clients and to staunch the flow of red ink, estimated this year at $3 million to $6 million—but hoped to wait a year. However, Medicare officials in Washington convinced them last week that acting now would benefit clients.