His presentation came as Democrats urge the Republican-controlled Legislature to expand Medicaid eligibility under the federal health care law. Haley repeated her opposition to the idea in her speech Wednesday. Keck, a member of Haley's Cabinet, also opposes covering an estimated 344,000 additional adults in South Carolina.
The federal government pledges to pay 100 percent of the added cost of newly eligible adults for the first three years, and 90 percent later.
"This is the deal of a lifetime," said House Minority Leader Todd Rutherford, D-Columbia, calling it a moral obligation to accept the coverage.
He and other Democrats contend Republicans are refusing to participate for ideological reasons that neglect the state's neediest.
But Republicans argue the state can't afford that eventual 10 percent and contend efforts to cut the federal deficit could leave states funding a much higher share.
Keck said the state needs to focus on improving the current system and reinvesting efficiency savings in improving residents' health.
The likelihood of Democrats winning their fight in the Republican-controlled Legislature seems slim. Democrats will try to get it passed through a budget clause. But the House's GOP majority is at its largest since Reconstruction, and that caucus has made refusing the expansion a priority for 2013. Though the federal law takes effect next January, the state doesn't have to decide on the expansion this year.
Rep. Harry Ott, D-St. Matthews, applauded Keck for his work.
"I predict you'll eventually expand Medicaid," he said. "The timing of when South Carolina decides to expand is what you and I may have a difference of opinion on."