States need to consider how they plan to implement strategies that might limit substitution. There are two major issues that may affect compliance with and evaluation of expanded programs which attempt to monitor substitution. First, several states have suggested that ensuring compliance with existing strategies to limit substitution is a cumbersome and expensive process. Second, the establishment of strategies to limit substitution, or "firewalls," may increase the complexity of the enrollment process, thus impeding the enrollment of eligible children. However, there are some examples of verification processes that are effective and efficient. Florida has utilized the National School Lunch Program as a method to verify eligibility of enrollees, and other state programs have used the verification processes of state Medicaid programs.