The author analyzes mainstreaming (as mandated by P.L. 94-142--the Education for All Handicapped Children Act) from an organizational perspective and maintains that resistance to the demands of mainstreaming is both natural and predictable. Mainstreaming terms are defined, an historical perspective is offered, and hypothetical case studies of handicapped children are given to illustrate representative school programs in three different time periods. Finally, a mainstreaming model is offered which looks at five factors that serve as facilitators and prohibitors of change: relative advantage, compatability, complexity, trialability, and observability. Ways to overcome barriers to mainstreaming (such as build a reward system) are also considered. (SBH)