The Gallup-Healthways Well-Being Index indicates 24 percent of Americans ages 18-26 were uninsured in January through April, down from 28 percent in 2010 and fewer than in 2009 and 2008.
As a result of the Patient Protection and Affordable Care Act, young adults in this age group became eligible last September to remain on their parents' health insurance plans.
The polls found more 18- to 26-year-olds say they get their healthcare coverage through "something else" other than an employer or the government -- this could be their parents' plans, a private health plan, or getting coverage through their college or university.
Adults ages 27-35 are now the least likely to be insured, Gallup says.
The survey involved telephone interviews of 102,584 U.S. adults, age 18 and older, living in all 50 U.S. states. It has a margin of error of 1 percentage point.