Since 2003, the Children's Health Initiative of Greater Los Angeles has sought to reduce uninsurance rates among children in Los Angeles County. Using the 2002/2003 Los Angeles County Health Survey to examine the variation in health care access and use among children with public coverage prior to the Initiative, it appears that certain subgroups are experiencing problems. The Children's Health Initiative of Greater Los Angeles will not have as great an impact on improving children's health unless these barriers are addressed.