HELENA -- The House narrowly endorsed a bill Tuesday that supporters say would increase the number of insured in Montana by offering potentially cheaper policies with limited coverage.

But the lone Democrat voting for the measure later said his vote was a mistake, so the measure likely will die on a final vote Wednesday.

Bill sponsor Rep. Tom McGillvray, R-Billings, said many young people are dropping their health insurance because it's too expensive. Much of that expense, he said, is being driven by the 40 types of state-mandated coverage in health insurance policies.

His proposal would allow insurance companies to offer policies that don't include several of those state mandates -- such as mental illness, mammographies, newborn care and home health care.

"What single man in his mid-20s would care about mammography? What man in his mid-20s would care about breast reconstruction surgery? ... We need to give these people a choice," McGillvray said.

Lawmakers endorsed his bill, 51-49, with Republican Rep. Bill Jones of Bigfork voting against it and Democratic Rep. Robin Hamilton of Missoula voting for it. A final vote is scheduled Wednesday.

Democrats railed against the bill as discriminatory and said there are better ways to reduce the cost of health insurance than limiting coverage.

"It's not by coincidence that we have these mandates," said Rep. Dave McAlpin, D-Missoula. "They are important and, overall, reduce the cost of health care."

Rep. Mary Caferro, D-Helena, argued the bill would only increase the number of underinsured Montanans, and questioned whether the limited coverage would really be cheaper.

McGillvray did not know the cost of such a policy. But he said figures cited by Blue Cross Blue Shield of Montana in a hearing on the bill show that insurance costs an average family of four more than $1,000 a year or $23 a month per person.

"This is about consumer choice and about freedom," McGillvray said. "As a state Legislature, we are in no position to be telling people what they need and what they don't need. We're in no position to be forcing mandates on people that they do not need."

He added the bill only gives the option to insurance companies, and does not eliminate any state-mandated coverage.

"Nothing in this bill requires a person to buy a limited coverage policy," he said.

Rep. Diane Sands, D-Missoula, criticized a provision at the end of the bill that she said would permit discrimination in the limited coverage policies based on sex and marital status.

"Health insurance based on gender is not the answer," she said.

McGillvray defended the provision, saying the state's unisex insurance law drives up costs for women.

The bill is House Bill 621.