FRIDAY, Aug. 19 (HealthDay News) -- The number of American children eligible for and enrolled in public health insurance programs increased between 2008 and 2009, a new study finds.

The number of children eligible for Medicaid/CHIP increased by about 2.5 million and rates of participation in the programs rose from 82.1 percent to 84.8 percent, according to the report released Thursday by the Robert Wood Johnson Foundation.

Participation in the programs increased across a number of demographic categories, including age, language group, race/ethnicity and family income level. Participation rates in 15 states and the District of Columbia were 90 percent or higher in 2009.

As a result of these nationwide increases, the number of eligible but uninsured children fell by about 340,000 between 2008 and 2009, according to the report.

However, about 4.3 million children who were eligible for public programs remained uninsured. Three states -- Texas, California and Florida -- accounted for nearly 40 percent of those children, the investigators found.

The increasing participation rates are likely due to ongoing federal and state efforts meant to boost enrollment and retention of children in the programs, the study authors said in a news release from the foundation.

More information

The U.S. Department of Health and Human Services has more about children's health insurance programs.