This brief examines variation in Medicaid/CHIP participation among children and parents. Participation continued to vary across states and subgroups of children but differences were found to be narrowing. Medicaid/CHIP participation increased nationally from 81.7 percent in 2008 to 85.8 percent in 2010, which was associated with a decline in uninsurance among eligible children. Participation rates were lower among parents in each state relative to the rates for children. States that had relatively higher/lower participation rates among children were more likely to also have relatively higher/lower participation rates among parents.