Uninsured Percentage, Personal Wealth and Medicaid Thresholds Were Determining Factors in CHIP Expansions, Study Finds

States with a higher percentage of uninsured children and a greater per capita personal income, along with lower income eligibility thresholds for children under Medicaid prior to the enactment of the Children's Health Insurance Program, had greater program eligibility limit differentials between Medicaid and CHIP than other states, according to a new study in the American Journal of Public Health. Using several sources of data, Frank Ullman of the Sapelo Research Group and Ian Hill of the Urban Institute evaluated the CHIP participation of all 50 states and the District of Columbia by comparing public health insurance eligibility limits for children ages 0 to 19 years in June 1997 -- a month before Congress enacted the program -- and in June 2000. They concluded that the "average state" raised its eligibility threshold from 121% of the federal poverty level under Medicaid to 206% under CHIP during that period. The study also found that three variables were statistically significant in predicting greater threshold increases; specifically, a "$1,000 increase in a state's per capita income was associated with a 3.75 percentage point increase" in CHIP eligibility levels, and states whose Medicaid income limits were in the bottom fifth were projected to raise their income thresholds by an average of 94 percentage points, while those in the top fifth were projected to raise theirs by 63 percentage points. The study also determined that changes in the amount of federal matching funds relative to Medicaid and the political affiliation of state legislatures and governors did not have a significant effect on income eligibility levels.

'Catching Up' With Other States
In the discussion of their findings, Ullman and Hill write that most states CHIP income limits "hover around the median" of 200% FPL. This means that CHIP eligibility levels "across states" are "more similar than they were in states' preexisting Medicaid programs." The range of income thresholds, however, is greater under CHIP because "some states, such as New Jersey at 350% FPL, have significantly expanded coverage beyond the thresholds of other states." The authors add that the finding that states with lower income limits under Medicaid increased their thresholds more under CHIP "suggests that ... states with previously low levels of coverage may be 'catching up' to those with historically more generous programs" (Ullman/Hill, "Eligibility Under State Children's Health Insurance Programs," September 2001). The full study is available online.