The number of people on Medicaid has been going up so rapidly in part because of decisions made by people like Lisa Sivers, a 30-year-old mother of three who lives in Binghamton.

She makes between $15,000 and $20,000 a year driving a bus for a preschool program while her 46-year-old husband stays home to care for their three boys, ages 9, 6 and 5.

Her employer offers health insurance, but she would have to pay about $40 every two weeks to get that coverage.

"That may not sound like a lot, but we have five people to feed,'' she said.

So instead, about 2 1/2 years ago, she signed up for Family Health Plus, a new Medicaid program available to so-called "working-poor'' families like hers. Unlike the regular Medicaid program, there is no limit on assets, like a house and car, that recipients can have.

The income limit for the normal Medicaid program for a family of five is less than $12,000 a year, but for Family Health Plus, the limit for that size family is just under $29,000.

She said the program has been important for her family. Recently her husband, who has diabetes, had a stent installed to open an artery, and he also needed to get new eyeglasses.

"It's been a lifesaver,'' she said.

But the program has helped to put serious holes in the budgets of counties, which have to pay 25 percent of the cost. The state pays its quarter share with the proceeds of a 55-cent-a-pack increase in the cigarette tax enacted in 1999.

"The state is providing an enormous incentive for employers to point people to Family Health Plus,'' said E.J. McMahon, a budget analyst for the Manhattan Institute, a business-backed think tank.