The share of US adults without health insurance rose 1.5 percentage point between fourth-quarter 2017 and fourth-quarter 2018 to 13.7 percent, according to the latest data from the Gallup National Health and Well-Being Index. That’s up from a low of 10.9 percent in 2016 and the highest level since January 2014, when the Affordable Care Act’s health insurance exchanges began offering individual market coverage and the first of 36 states began expanding Medicaid to low-income uninsured adults.