Hulshof said his self-described "bold initiative" could help low-income parents who were cut off from Medicaid three years ago, as well as small businesses that can't afford health insurance for their employees. He said state employees and workers who already have insurance also could choose to use his new insurance plan.

Hulshof calls it the Healthy Missouri Access Exchange, or HealthMAX for short.

"HealthMAX is a new marketplace that's designed to increase access to affordable health care for all Missourians," Hulshof said while announcing his plan at a heart center in Columbia. "It will be affordable not just for the consumers of health care but for taxpayers in our state."

Hulshof estimated it would cost $50 million to offer government subsidies to low-income Missourians participating in his plan, plus up to a couple of more million dollars to oversee the new program.

That's significantly less than the $700 million plan that Democratic candidate Jay Nixon outlined in July that would use a mixture of state and federal money to restore Medicaid coverage to the hundreds of thousands of low-income Missourians whose benefits were either eliminated or reduced in 2005. Nixon's plan also would allow middle-class families to buy into a government-run health care plan for their children.

Nixon, the attorney general, has made a top campaign issue of health care -- specifically the Medicaid cuts enacted by Republican Gov. Matt Blunt and the Republican-led Legislature. Republicans said the cuts in 2005 were necessary to balance the budget.

Hulshof, a congressman from Missouri's 9th District, has generally backed those cuts as a budgetary necessity. He proclaimed health care a priority last winter when he entered the race after Blunt chose not to seek re-election.

Hulshof waited to outline any health care specifics until several weeks after his primary election victory over Republican Treasurer Sarah Steelman on Aug. 5. He said he was consulting with health care professionals and putting together a carefully crafted plan.

On Tuesday, Hulshof repeatedly denounced Nixon's proposal as a return to a costly and poorly managed Medicaid system.

"Hitting the rewind button to go back to the 20th century is not the answer," Hulshof said.

Nixon is attending the Democratic National Convention this week in Denver. A spokesman for his campaign had no immediate comment Tuesday, saying the campaign had yet to analyze Hulshof's plan.

Last year, Blunt also announced a health care plan, dubbed Insure Missouri, to expand government-subsidized coverage for low-income workers. His plan faced stiff opposition in the House, including from fellow Republicans who were uneasy about increasing the government's role in health care.

House and Senate budget negotiators ultimately rejected the $375 million that had been proposed for Insure Missouri during the fiscal year that began in July.

Hulshof said his plan is different from Insure Missouri and from plans offered in other states as a means of covering uninsured people.

One key, he said, would be a requirement that ensures participation in HealthMAX could not be denied to people because of existing health conditions. Whereas that might normally make insurers reluctant to participate in the program, Hulshof said he hopes to spread their risk by creating a pool of about 200,000 low-income people getting government insurance subsidies, as many as 60,000 state employees and others with private sector jobs who choose to opt into the pool.

Individuals would purchase their own health insurance plan by picking among various options. Businesses also could make contributions to the plan on behalf of employees.

For low-income Missourians, the state would pay the premiums of insurance plans connected to a health savings accounts. The participants would be expected to contribute up to 5 percent of their income. All participants would be guaranteed access to at least $500 in annual preventive health care, Hulshof said.