The increase in undocumented immigration between 1999 and 2007 contributed to an increase in the number of uninsured people in the United States.
During this period, the number of undocumented immigrants increased from an estimated 8.5 million to 11.8 million, leading to an estimated additional 1.8 million uninsured. These uninsured and undocumented immigrants were estimated to represent 27 percent of the overall increase of 6.9 million uninsured people during this period. Undocumented immigrants accounted for one in seven of the uninsured in 2007, up from one in eight in 1999. These undocumented immigrants will not be eligible for public insurance or any type of private coverage obtained through exchanges under the Affordable Care Act of 2010. As a result, members of this group will eventually constitute a larger percentage of the uninsured population, unless other policy actions are taken to provide for their coverage, or their immigration status is changed.