The report, released Monday, said millions of people cannot afford to pay for medical needs, including insurance, presciption drugs, eyeglasses, mental health and dental care.
The report, by the CDC's National Center for Health Statistics, provides statistics in various categories.
For example, in 2005, one of five people under 65 reported being uninsured for at least part of the 12 months prior to being interviewed .
Also in 2005, nearly one in 10 adults between 18 and 64 said they were unable to get necessary prescription drugs due to cost, and a similar number delayed receiving medical care.
One in 10 women ages 45 to 64 with income below the poverty level reported delaying medical care due to lack of transportation, and about one-third of all children living below the poverty level did not have a recent dental visit in 2005.
"This report shows that access to healthcare is still an issue where we need improvement," said Dr. Julie Gerberding, director of the CDC, said in a statement.