Senator Eliot Shapleigh - El Paso, Texas

WASHINGTON — Congress is poised to give President-elect Barack Obama a quick victory by passing a bill to provide health insurance to millions of low-income children.

The House Democratic leader, Representative Steny H. Hoyer of Maryland, said the bill, scheduled for a vote in the House this week, was “very much like” legislation twice vetoed by President Bush in 2007. Legal authority for the program expires on March 31.

Congressional Democrats said they had decided to add a major provision allowing states to restore health insurance benefits to legal immigrants under 21, a goal of Hispanic groups since those benefits were terminated in 1996.

This part of the bill deals only with legal immigrants. But it could revive the emotional debate over immigration, as many Republicans want to establish stricter verification procedures to prevent illegal immigrants from getting health benefits.

Under current law, legal immigrants are generally barred from Medicaid and the State Children’s Health Insurance Program for five years after they enter the United States. The Democrats’ proposal would give states the option of covering children and pregnant women, with the federal government subsidizing the costs as usual under both programs.

Supporters of the bill said it would cover 10 million children, providing benefits for nearly 4 million who are uninsured, while continuing coverage for 6.6 million youngsters already enrolled. The federal government now spends more than $5 billion a year on the program, and while precise figures are not yet available, the expansion would more than double that cost.

Experts estimate that 400,000 to 600,000 immigrant children affected by the restrictions could get insurance under the bill.

“Children should not be forced to wait five years for health care,” said Jennifer M. Ng’andu, a health policy specialist at the National Council of La Raza, a Hispanic rights group. “Five years is a lifetime to a child.”

Representative Eric Cantor of Virginia, the Republican whip, said Republicans had concerns about expanding the program, to immigrants or any other group, before the original purpose of the program was achieved.

“The program has not fulfilled its initial mission, to serve children of the working poor,” Mr. Cantor said in an interview.

Among children, legal immigrants are less likely than citizens to receive immunizations and routine dental care. Likewise, among women, legal immigrants are less likely to receive prenatal care.

Leighton C. Ku, a professor of health policy at George Washington University, said the five-year wait had harmed children who would become citizens. “About half of all low-income immigrant children are now uninsured,” Mr. Ku said. “Most immigrant children become U.S. citizens. When they grow up, they make contributions to the economy, pay taxes and serve in the military.”

Aides to Speaker Nancy Pelosi briefed advocacy groups on their plans on Friday.

“There were cheers in the room,” Ms. Ng’andu said. “It was a joyous moment when we learned that legal immigrant children would be covered.”

House Democrats are taking their bill directly to the floor, but in the Senate, Democratic leaders plan to work through the Finance Committee, led by Senator Max Baucus, Democrat of Montana. Mr. Baucus has drafted a bill similar to the House measure. As of late Monday, his proposal did not include benefits for immigrants.

But other Democratic senators, like Jeff Bingaman of New Mexico and John D. Rockefeller IV of West Virginia, have said that they, like Mr. Obama, want to allow states to cover children who are legal immigrants.

The new bills, like those vetoed, would be financed by tobacco taxes, including a 61-cent cigarette tax increase, to $1 a pack.