Heading into a December 15th deadline, nearly 90,000 Tennesseans have signed up for health insurance exchange coverage through the affordable care act. Chattanooga—based Blue Cross—Blue Shield of Tennessee taking the lion’s share of the exchange market in the state. Last year the non-profit accounted for some 70 percent of all enrollees in Tennessee. Blue cross is jumping renewal rates by an average of 36 percent after posting heavy losses during the 1st 2 years of the program. The federal government is helping to offset monthly premiums for many who qualify for tax credits. Nationwide nearly 1 million new customers signed up for coverage through the federal exchange program as of Saturday. Consumers must sign up by December 15th to have health coverage on January 1st. Open enrollment runs through January 31st, 2016.