Health care legislation adopted by House Republicans earlier this month would leave 23 million more Americans uninsured within a decade, the Congressional Budget Office projected Wednesday – only a million fewer than the projection for the House’s earlier bill.

The finding, which is sure to draw fire from Democrats, patient advocates and many health industry officials, could complicate Republicans’ push to pass a companion bill in the Senate.

The new estimate, which reflects a series of last-minute revisions Republicans made to win over several conservative lawmakers and a handful of moderates, calculates that the American Health Care Act would reduce the federal deficit by $119 billion between 2017 and 2026. That represents a smaller reduction than the $150 billion CBO estimated in late March, largely because House leaders provided more money in the final bill to offset costs for consumers with expensive medical conditions and included language that could translate to greater federal spending on insurance subsidies.

While House Republicans pressed ahead with a final vote without getting a precise cost estimate in advance, Wednesday’s CBO score will now help shape what sort of measure can be crafted in the Senate. To avoid a filibuster, Senate Republicans plan to take the bill up under budget reconciliation rules, which only require a majority vote, but it means the legislation cannot increase the federal deficit within a 10-year window.

The bill the House narrowly passed on May 4 meets that test and would rewrite large portions of the Affordable Care Act, which Republicans have pledged to dismantle for more than seven years. But Senate Republicans have been working for weeks to craft their own health care bill and emphasize that they have no plans to simply take up the House’s legislation.

“The CBO score on the Senate bill is going to be what counts,” Senate Majority Whip John Cornyn, R-Texas, said earlier Wednesday.

Joseph Antos, a resident scholar at the libertarian American Enterprise Institute who specializes in health care, said the new estimate “is the same signal repeated,” conveying that the changes congressional Republicans envision would cut the price of premiums and trim the deficit while leaving more Americans without insurance.

The AHCA’s proposal to cut spending on Medicaid – a federal program that covers roughly 69 million Americans – by $880 billion over the next decade is the thorniest political issue facing the Senate, Antos said.

“They’re going to have to do something on Medicaid, and that something is a real question,” he said.