WASHINGTON » The House of Representatives easily passed bipartisan legislation Thursday to update the way Medicare pays physicians and extend federal funding for a popular children’s health insurance program, putting pressure on the Senate to act before Congress recesses Friday.

But prospects were dimming late Thursday that Senate leaders would take up the package to avert an automatic 21 percent cut in Medicare payments to physicians that is scheduled to go into effect Wednesday.

Several Republican senators voiced concern about the bill’s impact on the deficit, which could potentially preclude Senate Majority Leader Mitch McConnell, R-Ky., from bringing up the bill Friday in an expedited maneuver that under Senate rules requires unanimous consent.

Democrats remain concerned that the legislation reauthorizes funding for the Children’s Health Insurance Program, or CHIP, for only two years, rather than four, as many advocates and governors want.

Unless the Senate acts Friday, lawmakers probably won’t consider the legislation until returning to Washington on April 13.

Medicare officials can delay the pending fee cut for 10 working days after Wednesday. But after April 14, physicians would begin to see the smaller Medicare reimbursements.

The overwhelming 392-37 vote in the House may help major medical groups and other supporters get the package through the Senate next month, however.

President Barack Obama endorsed it Wednesday. Dozens of influential interest groups on the left and right have rallied behind it, despite lingering opposition to parts of the package from across the ideological spectrum.

The bill brought together Republicans and Democrats in a rare bit of compromise to address pressing health care issues.

"It will help ensure that seniors have access to their doctor, and put in place a stronger Medicare program to aid every American who (is) trying to care for their elderly parents," House Speaker John A. Boehner, R-Ohio, said Thursday.

The new Medicare fee system would replace a widely discredited program known as the Sustainable Growth Rate that subjects physicians to nearly annual threats of fee cuts, which Congress has routinely voted to override.

The new system would impose more regular 0.5 percent fee increases over the next four years and create modest incentives to reward physicians who hit quality and efficiency targets.

The two parties agreed not to offset most of the $200 billion cost of the legislation, a move that forced Republicans to buck budget hawks who have complained that the package would add $140 billion to future budget deficits.

Democrats, meanwhile, agreed to a shorter CHIP extension and to new cost-sharing requirements for Medicare beneficiaries, including a restriction that stops Medigap plans from paying beneficiaries’ $147 deductible for physician services. Millions of seniors rely on these commercial plans to help pay for out-of-pocket medical expenses not covered by Medicare.

To renew funding for community health centers, Democrats also went along with long-standing restrictions on the centers’ use of federal funding for abortion services.

"While we would like to see this legislation strengthened … this compromise legislation takes an important step in Medicare payment reform and ensures continued funding that improves the health and welfare of millions of children, families and seniors," the left-leaning Center for American Progress said.