Studies by the Commonwealth Fund, the Urban Institute and the Gallup organization all agree that sign-ups under the Affordable Care Act (ACA) totaled at least 8 million. Nationwide, that equates to one in four previously uninsured being covered for their health care in 2014.

The biggest gain came in California, where the uninsured were reduced by half, from 22 to 11 percent of the population. Almost two-thirds of the newly covered, however, were enrolled in Medi-Cal, the state's free Medicaid program for the poor.