The Affordable Care Act (ACA) requires that Medicaid cover children with incomes up to 133 percent of the federal poverty level (FPL) ($31,322 for a family of four in 2013) as of January 2014. Today, there are “stairstep” eligibility rules for children. States must cover children under the age of six in families with income of at least 133 percent of the FPL in Medicaid while older children and teens with incomes above 100 percent of the FPL may be covered in separate state Children’s Health Insurance Programs (CHIP) or Medicaid at state option. While many states already cover children in Medicaid with income up to 133 percent FPL, due to the change in law, 21 states needed to transition some children from CHIP to Medicaid. This brief examines how the transition of children from CHIP to Medicaid will affect children and families as well as states. The brief also looks to New York and Colorado for lessons learned from the early transition of coverage.