This study provides an evaluation of the national and state level educational environmental placement trends for students, ages 6-11 or 12-17, with learning disabilities (LD), emotional disabilities (ED), mental retardation (MR), or speech and language impairments (SLI) in the decade following implementation of the Regular Education Initiative (REI) promulgated in the late 1980s. REI called for greater access to general education curricula for students with disabilities and led to changes in the Individuals with Disabilities Education Act and the ideology of inclusion. Results reveal overall small, but statistically significant, increases in the use of more inclusive environments since the REI, but the extent of changes varied at the state level, between age groups and among disability categories. Students with speech language impairments or learning disabilities were placed in general education environments at a higher rate than those identified as emotionally disturbed or mentally retarded. Analysis also indicated that the percent of students with disabilities receiving services outside general education more than 60% of the time remained relatively consistent from 1989 to 1999. Finally, the study found temporal relationships between changes in placement rates and the implementation of federal reforms directed toward improved educational outcomes for students with disabilities through greater inclusion in general education. (Contains 19 references.) (DB)