Ned Lamont and governors from 17 other states are calling on congressional leaders to extend federal subsidies that help more people afford health coverage through state-based insurance exchanges like Access Health CT. The subsidies, known as enhanced premium tax credits, are set to expire at the end of the year. If they do, states will have to pick up the cost — or individuals will pay significantly more for health coverage. Connecticut residents who get insurance through the state health care exchange could pay an average of $1,700 more a year. “Health insurance and these premium tax credits are absolutely essential to lowering the cost of health care.”Blumenthal has co-sponsored federal legislation that would make the enhanced premium tax credits permanent.