WASHINGTON — Five years of progress reducing the number of Americans without health insurance has come to a halt, according to a government report out Tuesday. More than a factoid, it shows the stakes in the Republican drive to roll back the Affordable Care Act.

The report from the Centers for Disease Control and Prevention estimates that 28.6 million people were uninsured in 2016, unchanged from 2015. It was the first year since passage of the health care overhaul in 2010 that the number of uninsured did not budge.

The uninsured rate for 2016 was 9 percent, an insignificant difference from 9.1 percent the previous year. When former President Barack Obama signed the ACA in 2010, the uninsured rate had been 16 percent.

Tuesday’s report suggests that the ACA was running low on gas in Obama’s final year as president. Premiums for private insurance were about to jump, and 19 states continued to refuse the law’s Medicaid expansion.

Now, the number of uninsured could start climbing again under policies being considered by President Donald Trump and congressional Republicans.

The politically unpopular GOP bill passed narrowly by the House would limit Medicaid financing and curtail subsidies for many consumers buying their own private policies. Republicans also would repeal the requirement that most Americans carry health insurance or risk fines, a much-disliked nudge to get healthy people covered.

The legislation would lead to an estimated increase of 24 million uninsured people within 10 years, according to congressional analysts. Under “Obamacare,” there are 20 million fewer uninsured since 2010.

“It’s disappointing that it’s stalled out,” said health economist Gail Wilensky, a Republican. “The real question is, will we be able to keep the gains that we have made?” Critical of the ACA and co-author of an alternative plan by GOP policy experts, Wilensky nonetheless supports the goal of expanding coverage. She’s concerned about the impact of the House bill on Medicaid, the federal-state program for low-income and disabled people.

The new numbers come from CDC’s National Health Interview Survey, which is considered an authoritative source, and publishes findings earlier than the Census Bureau. Estimates for 2016 were based on data for nearly 97,500 people.