Rates of coverage varied by state as well.
"For example, 3.8 percent and 5.2 percent were uninsured in the District of Columbia and Massachusetts, respectively, whereas 24.8 percent were uninsured in Nevada and 24.7 percent were uninsured in Florida," NCHS statisticians wrote.
In states that are not expanding Medicaid coverage, "state differences in uninsurance may well become even greater," said Katherine Hempstead, team director and senior program officer at the Robert Wood Johnson Foundation in Princeton, N.J.
A majority of adults -- 64.2 percent -- had private health insurance coverage in 2013.
Of those who get health coverage on the job, nearly one-third (32 percent) were enrolled in a high-deductible health plan, compared with 17 percent in 2008.
"This is a near doubling in a period of less than 10 years," Hempstead noted. "This is clearly becoming the new norm, and the marketplace plans will only increase the rapidity of this trend," she added.
Among other findings in the reports:
- Asthma prevalence among people of all ages dropped to 7.4 percent in 2013 from 8.6 percent in 2010 and 2011.
- Twenty-nine percent of adults aged 20 and older were obese in 2013, versus 19.4 percent in 1997.
- Among adults 18 and older, 9.3 percent had been diagnosed with diabetes, compared with 9.1 percent in 2012 and 5.1 percent in 1997.
Will the Affordable Care Act address these disparities?
"What public health researchers are hoping to see . . . is how this humongous growth in health insurance translated not only to access to care, but better health outcomes," Lavarreda said.