Under the Affordable Care Act, uninsured rates have narrowed for both black and Hispanic adults, yet Hispanics and blacks continue to face huge gaps in coverage, according to a new study.

Expanded coverage under the Affordable Care Act (ACA) has reduced the number of uninsured individuals and disparities facing diverse populations in the U.S. health care system. Also, the law has increased gains among diverse U.S. populations.

The ACA increases access by making financial assistance reachable for the newly eligible. It has also reduced some of the persistent disparities, expanded Medicaid eligibility to low-income nonelderly adults, and increased investments in outreach designed to promote enrollment. Additionally, ACA has an emphatic focus in increasing health insurance literacy and enrollment in simplification and coordination across Medicaid and the Marketplaces.

The report "Under the Affordable Care Act" will appear in the October issue of Health Affairs. The report used data from the National Health Interview Survey to calculate two measures of disparities, "absolute disparity" and "relative disparity."

According to the report, "absolute disparity" is the difference between the percentage uninsured for Hispanics or blacks and whites, while "relative disparity" examines the ratio of the percentage uninsured for Hispanics or blacks to white. The study found there have been reductions in the absolute disparity declined for Hispanics and blacks in expansion and nonexpansion states, though large gaps still existed. Also, study authors cautioned shifts in relative disparities in uninsurance were mixed, and gaps persisted for Hispanics and blacks in expansion and nonexpansion states in 2014. In expansion states, Hispanics were 3.2 times more likely to be uninsured than whites in 2014, compared to 2.7 times in 2013.

The study focused on the periods just before and after the first ACA enrollment period. The uninsured rates for Hispanics (both citizens and noncitizens) declined to 31.8 percent from 40.1 percent in the third quarter of 2013. Uninsured rates also declined from 25.5 percent to 17.2 percent for Blacks and reduced from 14.7 percent to 10.5 percent for whites.

Despite decreases and continued efforts, complete coverage has been limited by at least two factors. According to the research, individuals with incomes below the federal poverty line are not eligible to receive subsidies to purchase Marketplace coverage. These subsidies are only made available to those who possess income of 100-400 percent of poverty. Also, undocumented immigrants are ineligible for Medicaid, and they are unable to purchase subsidized coverage through the Marketplaces. Approximately 16 percent of Hispanics are undocumented, revealing that nearly one-fifth of the Hispanic population does not have access to ACA. Furthermore, documented non-English speakers require additional assistance when attempting to access marketplaces.

Stacey McMorrow, Sharon K. Long, Genevieve M. Kenney, and Nathaniel Anderson authored the study as part of the journal's reestablished DataWatch series. The new study was released by Health Affairs as a Web First.