The rate of Americans without insurance held steady at a historic low of 8.8 percent in the first year of President Donald Trump's administration, according to a new report from the U.S. Census bureau.

The data paint a picture of stable health insurance coverage, across both private and government health plans, in a year that saw repeated efforts by the White House and Republicans in Congress to repeal Obamacare and to roll back provisions for the expansion of Medicaid.

Yet, it was the first year since the full implementation of the Affordable Care Act that did not see a drop in the uninsured rate. From 2013 to 2017 the national uninsured rate dropped 4.5 percentage points.

"The progress in covering people uninsured under the ACA was historic, but it had already started to stall before President Trump took office," said Larry Levitt, senior vice president of the Kaiser Family Foundation.

While the actual number of people who were uninsured rose slightly in 2017 to 28.5 million, up by about 400,000 from 2016, that nominal increase was not statistically different from 2016, according to the Census Bureau's Current Population Survey.

Among working adults, younger millennials and people 45 to 64 were the only age groups to see a slight increase in coverage last year, at 0.1 percentage points.

The percentage of adults between the ages of 19 and 25 with health insurance fell by 0.9 percentage points to 86 percent.

The highest uninsured rate continues to be among 26-year-olds; that's the age at which young adults age out of the ACA provision that allows them to be covered under their parents' plan. That resulted in Americans between the ages of 26 and 34 continuing to have the lowest rate of insurance coverage, at 86 percent last year.

The big question now is how the Trump administration and Republicans in Congress will change coverage over the next year.

"It's quite possible we'll start to see the uninsured rate climb over the coming year as changes from the Trump administration and Congress take hold, especially repeal of the individual mandate penalty," Levitt said.

The Tax Cuts and Jobs Act passed nearly a year ago repealed the individual penalty for not having health coverage starting in 2019. The Congressional Budget Office has estimated that measure will result in 3 million people losing their coverage next year.