Examining Substitution: State Strategies to Limit "Crowd Out" in the Era of Children's Health Insurance Expansions. C. There are various types of data states may need to collect in order to measure substitution.


Most states did not initially identify substitution as a major concern in current efforts to provide coverage to uninsured children. As a result, states did not conduct initial surveys or evaluations to quantify rates of substitution and the long-term impact of employees and employers substituting for private coverage. In order to assist states in determining types of data to collect, the following is a list of information that may be useful in effectively quantifying substitution:

  • What are the characteristics of the target population covered by state's current programs? Income levels? Differences at various levels (150 vs. 200)? Access to employer coverage? Health status? Other characteristics?
  • What has the states' enrollment experience been: at different income levels; different age groups? For different employment status; other characteristics influencing enrollment?
  • From where do program participants come and where do they go when they leave the program? From or to Medicaid? From or to private coverage? From or to no coverage?
  • There are various program features that may relate to either increasing or decreasing the likelihood of crowd out. What are the issues around crowd out that were considered in designing the state's program? Who raised these issues? How were the issues addressed in the design? How did actual experience match up with expectations? How was the program modified to reflect these experiences?
  • Do states perceive crowd out to be different between Medicaid coverage and other types of government supported coverage?