Every quarter, Gallup posts the results of an exhaustive healthcare coverage survey (with over 25,000 U.S. adults). They just posted the latest update, which covers the fourth quarter of 2017, and the results are...striking.
Gallup has a rather annoying habit of not including the full Y-axis in their charts, so I've reformatted their quarterly survey results into a fuller version, noting a couple of key dates. The most obvious takeaway:
The U.S. uninsured rate among adults, which had reached 18% just before the major Affordable Care Act provisions (individual market exchanges and Medicaid expansion) kicked into effect, reached an all-time low of 10.9% last winter...
...only to reverse the trend since then, climbing back up again over the first year of the Trump Administration to end 2017 at 12.2%.
One important thing to keep in mind is that Gallup's surveys only include adults over 18, which means they only include about 77% of the population. Since children tend to have a much lower uninsured rate than adults (thanks in large part to programs like Medicaid and CHIP), this skews the results for the total population by several percentage points.
Instead, this time they've broken the numbers out by state:
WASHINGTON, D.C. -- Arkansas and Kentucky continue to have the sharpest reductions in their uninsured rates since the healthcare law took effect at the beginning of 2014. Oregon, Rhode Island and Washington join them as states that have at least a 10-percentage-point reduction in uninsured rates.