The Obama administration says the number of young adults going without medical coverage has shrunk by 2.5 million since the new health care law took effect.
A new analysis to be released Wednesday finds the drop is two-and-a-half times the figure indicated by government and private estimates from earlier this year.
The health care overhaul allows young adults to stay on a parent's plan until they turn 26.
Administration analysts found that nearly 36 percent of Americans age 19-25 were uninsured in the third calendar quarter of 2010, before the law's provision took effect.
That's over 10.5 million people.
By the second calendar quarter of 2011, the uninsured dropped to a little over 27 percent, or about 8 million.
The difference is nearly 2.5 million more young adults getting coverage.