In Arizona, where state revenues are down 31 percent, the governor called an emergency cabinet meeting last week as the Senate bill was advancing and ordered the state to stop accepting applicants to its children’s health insurance program. The state, where voters approved an expansion of Medicaid in 2000, projects that in the first seven years of an overhaul, its share of Medicaid would be $17 billion under the Senate bill. Had Arizona not expanded coverage, the state’s share would have been $1.4 billion, the state estimates.

“You’ll have taxpayers in Arizona raising taxes on themselves not only to support their program, but to cover all the other states expanding,” said Thomas J. Betlach, the Medicaid director in Arizona. “I work for an insolvent entity; we can’t afford the program we have.”

The House bill would take effect in 2013 and expand Medicaid to cover Americans earning up to 150 percent of the federal poverty level, currently about $29,300 for a family of four and $14,400 for an individual. The Senate bill would begin in 2014 and extend Medicaid to Americans making up to 133 percent of the federal poverty level.

Under the Senate bill, the federal government would pay the entire cost of expanding Medicaid to those not already eligible under state coverage for the first three years of the program. The following three years, states that do not now have expanded coverage would be reimbursed at a higher rate than those states that do  in general, the states without expanded coverage would be paid back 95 percent of their costs, while those that have already expanded coverage would be reimbursed between 80 percent and 95 percent. Medicaid reimbursement rates are based on per capita income; wealthier states have smaller shares of their costs paid back.

The biggest hit to states that have already expanded will be in covering the people who are eligible now but have not signed up for coverage under the state’s current program. They are expected to enroll because the new legislation will require almost all Americans to have insurance.

States that have expanded already would not get any new matching funds for those people. The Senate bill provides additional money only for those who are “newly eligible.”

For example, the federal government would pick up the entire cost for the first two years and 95 percent of the cost for the next three years for newly covered working parents in Alabama, which now covers only those making up to 24 percent of the federal poverty level.