A new survey shows that states that created their own health marketplaces have an uninsured rate that is about half that of states that rely on federal marketplaces.

The survey conducted by the U.S. Centers for Disease Control and Prevention (CDC) demonstrated that California's uninsured rate dropped to 6.8 percent in the first six months of this year, down from 17 percent in 2013.

"California is not alone in the historic gains made possible by the Affordable Care Act," Peter V. Lee, executive director of Covered California said.

"This new survey shows that overall, state-based marketplaces continued to reduce the rates of their states' uninsured, while those states while those states supported by the federal marketplace saw the first uptick in their uninsured since 2014."

Other states seeing uninsured rates below eight percent include Illinois, Michigan, New York, Ohio and Pennsylvania.