The Medicare supplement plan type with the biggest market share continues to gain share.
The number of Medicare enrollees who signed up for Medigap Plan F coverage increased to 4.6 million in December 2011, up 9.6% from the total in December 2010.
Plan F enrollees accounted for about 51% of all Plan F enrollees in 2011, up from 47% in 2010.
Many plan types recorded a drop in the number of enrollees they covered and the share all Medigap users they covered.
One major plan type, Plan C, ended 2011 with 1.3 million enrollees, down 6.6% from the total recorded a year earlier.
Plan C's share of the Medigap market fell to 14%, from 16%.
In 1998, Plan C was the most popular Medigap plan type.
A research center at America's Health Insurance Plans (AHIP), Washington, has reported those figures in an analysis of figures from the Medigap exhibits that insurers filed with the National Association of Insurance Commissioners (NAIC), Kansas City, Mo., for the year that ended Dec. 31, 2011.
AHIP says overall enrollment in the "standardized" Medigap plans designated by letters increased 1.7%, to 9.1 million. About 9.8 million people were enrolled in all types of Medigap plans, including plans purchased before July 1992, when the current standardization rules took effect.
The federal government requires health insurers to use standardized plan types designated by letters when developing and selling Medigap coverage.
Plan F coverage fills many of the gaps left by the traditional Medicare Part hospitalization program and the Part B physician services program.
Plan F will pay for the first 3 pints of blod, for example, and it also will pay the Part A hospice care coinsurance or copayment amount. Part F also will pay skilled nursing facility care coinsurance bills, Part A and Part B deductibes, some foreign travel emergency bills, and physician fees that Medicare Part B classifies as "excess charges."
Plan C plans will cover most of the same expenses, but they won't cover Part B excess charges.