For political and implementation reasons, most of the Affordable Care Act won’t take effect until 2014. Among the provisions that have begun, however, is a change that allows young adults (men and women immediately out of college) to remain on their parent’s health insurance plans. As this new Gallup poll shows, this small change has yielded a big effect:

Here’s Gallup with an explanation, “About one in four (24.2%) 18- to 25-year-olds reported being uninsured in the second quarter of this year, down from 28% in the third quarter of 2010, and nearly the lowest Gallup has measured at any point since it began tracking health insurance coverage rates in 2008.”