The number of Americans without health insurance plunged after Obamacare started. Now, early evidence suggests, it’s beginning to climb again.

New polling from Gallup shows that the percentage of uninsured Americans inched up throughout last year. That trend matches other data suggesting that health coverage has been eroding under the policies of the Trump administration.

Gallup estimated that the uninsured rate for adults increased by 1.3 percentage points. That would mean an increase of more than three million people without insurance between the first quarter of 2018 and the end of the year. Gallup said this was a four-year high, although a major methodology change a year ago may make such longer-term comparisons less precise.

“There’s no question that some of the reductions in the uninsured rate that we have measured over the course of Obamacare has now been given back,” said Dan Witters, the research director for the survey.