This analysis examines the demographics of the special needs population in public and private schools in Oklahoma and estimates the impact on school enrollments providing tax credit funded scholarship grants for special needs students. The author and his colleagues develop a model that shows how the expenditures of Oklahoma's school districts vary with enrollment changes for both regular and special needs children, and show the state and local fiscal impacts of a special needs tuition tax credit program. Their analysis indicates that school district expenditures are affected much more by enrollments of special needs students than they are by enrollments of students not needing special services. They conclude that a tuition tax credit funded scholarship program would generate significant scholarship demand among the population of special needs students in public schools. Based on the structure of the program and the expenses associated with each student who participates they also conclude that a program could be structured that would yield fiscal benefits to the state of Oklahoma. Additionally, for almost any program structure, special needs tuition tax credits are likely to yield large fiscal benefits to local school districts. Although not the basis of their research, recent research on special education scholarships indicates that increased parental satisfaction and higher levels of student performance result for participants in a special needs scholarship program. (Contains 9 tables, 5 figures and 20 endnotes.) [This study was released jointly by the Friedman Foundation for Educational Choice and the Oklahoma Council of Public Affairs.]