At legislative direction in the 1994 Supplemental Appropriations Act, the Washington State Institute for Public Policy is assessing the feasibility of doing a longitudinal study of educational outcomes for students in special education. A longitudinal study allows the tracking of a population over some period of time in order to document changes in that population. Conducting such a study in the field of K-12 education will be complicated and costly. In Washington State, we have had only limited experience with this approach. This report provides a summary of what is known from the research literature on outcomes for special education students who graduate from high school in the U.S. and in Washington State.