Congressional negotiators announced a roughly $80 billion deal on Tuesday to expand the federal child tax credit that, if it becomes law, would make the program more generous, primarily for low-income parents, as soon as this year.

The bipartisan agreement was reached by Senate Finance Committee Chairman Ron Wyden (D-Ore.) and House Ways and Means Committee Chairman Jason T. Smith (R-Mo.), who had been trying to finalize a deal for months. But any bill’s path to passage remains uncertain, particularly because House Republicans may be reluctant to give President Biden even a partial victory on one of his top domestic economic policy priorities: bringing back something like the expanded child tax credit, which was a centerpiece of his 2021 American Rescue Plan.