In 2008, before Congress created the new 65% group health benefits continuation subsidy, few eligible departing workers were signing up for COBRA benefits, a research service reports.

Spencer’s Benefits Reports, Riverwoods, Ill., says about 17% of U.S. employees became eligible for continuation benefits under the Consolidated Omnibus Budget Reconciliation Act in 2008.

Only about 9.7% of the departing workers who were eligible for COBRA benefits signed up for coverage, according to Spencer’s, a unit of Wolters Kluwer.

For employers, COBRA cost an average of about $11,000 per participant, up 32% from $8,353 in 2004.

That compares with an average benefits cost of about $7,200 per year for active employees, Spencer’s says.