Sales of traditional Medicare supplement insurance plans continue to increase, a market data firm says.

The number of Medigap policies in force that had been issued in the previous 3 years issued increased 1.25% in 2009, according to Mark Farrah Associates, Kennebunk, Maine.

The 2009 growth rate was down from a Medigap new-policy count growth rate of 2.67% in 2008, Mark Farrah says.

Medigap carriers are preparing to introduce new Plan M and Plan N policies June 1, and that might have affected the 2009 new-policy count, the firm says.