Mudrick (2002) summarizes two different paradigms that have been developed to compile statistics for the population of children with disabilities. The first classifies disability based on activity limitations, defined as the inability "to attend school or play, or engage in other age-normative activities" (Mudrick, 2002). Based on these criteria, approximately 6.5% of all children under the age of 18 (4.4 million), have a disability. However, this figure slightly underestimates the total because it does not include children who are institutionalized because of their disabilities (Mudrick, 2002). A second approach to determining the number of American children with disabilities is the functional limitation paradigm. Functional limitations are defined as "restrictions in activities due to chronic health conditions" (Mudrick, 2002). Using this definition, about 14.8% of all children under age 18 (10.3 million) have chronic disease or disability (Mudrick, 2002). Estimates using the second approach are much greater because they include "children whose service use is beyond routine," a requirement for the identification of Children with Special Health Care Needs (Mudrick, 2002). This classification helps children tap into funding streams through the Maternal and Child Health Bureau's Title V program for a variety of social service programs (Mudrick, 2002).