NASHVILLE (AP) - Projections for enrollment in Gov. Bill Haslam's proposal to cover low-income Tennesseans have been revised upward to 280,000 people in the first year.

The Republican governor's chief of staff, Mark Cate, said Wednesday that new number reflects the results of actuarial studies and comparisons with Medicaid programs in other states. The original estimates for the Insure Tennessee plan had pegged the expected enrollment at 200,000 or less.

Cate added that while the enrollment projections have gone up, the estimated cost per enrollee has gone down enough to keep cost expectations at their original level. The Insure Tennessee proposal would be available to people whose earnings are below 138 percent of the federal poverty level - which works out to $16,100 for an individual or about $33,000 for a family of four.

Cate and other members of the Haslam administration presented details about the plan to state lawmakers in adva nce of next week's special session to decide its fate. The officials stressed that the plan wouldn't come with any cost to Tennessee taxpayers because state hospitals have agreed to cover any extra expenses.

Several Republican legislators raised questions about committing to the program that draws on federal money available under President Barack Obama's health care law, and that participating would contribute to country's fiscal issues.

"If we don't participate and it doesn't increase the national deficit, then that's money that doesn't have to be paid back in the future by Tennesseans," said Sen. Kerry Roberts, R-Springfield.

Cate declined to speculate on whether approving the program would add to the federal deficit, but noted that Tennessee already receives wide range of federal funding in areas like education and transportation. About 40 percent of the state's current $32.9 billion spending plan comes from federal sources.

Cate emphasized that the state contributes taxes and fees related to the federal health care law regardless of whether it draws down money for Medicaid expansion.

"Our clear point is we are already paying for this," Cate said. "And we're not getting anything in return."

Republican Rep. Andy Holt of Dresden appeared unconvinced by the presentation.

"Even though we say it's free market system, or a market-based system, we're still buying in to a losing book of business," Holt said.

Holt took issue with estimates that about 46 percent of those covered under the proposal would be unemployed. Wendy Long, the chief medical officer for TennCare, responded that a large percentage of those unemployed adults have physical or mental health conditions.

"Perhaps with good medical care could return to the workforce," she said.

The governor has been on the road to promote his Insure Tennessee proposal and wraps up the statewide tour with stops in Johnson City, Sparta and Murfree sboro on Thursday.