Incidence figures for special education placement in a sample of 94 U.S. school districts were calculated. During the 1977-78, 1978-79, and 1979-80 school years, about 5% of the students were referred and evaluated; 3% were placed in special education programs. Wide variation was evident in the incidence figures for individual school districts, with some reporting placement incidence as high as 21% of the school population. The results are viewed as evidence of a need for proactive thinking in special education with regard to a reasonable rate of growth relative to the likelihood of continued reductions in financial support. (Author)