During the 1960s and 1970s, state-level comprehensive planning was established as federal policy prerequisite to state participation in many federal grant-in-aid programs. This study traces the evolution and operation of this policy through the Developmental Disabilities (DD) program (as enacted through the Developmentally Disabled Services and Facilties Construction Act of 1970, P.L. 91-517). The perceptions of DD State Planning Council members and staff--the "participant planners"--from four states are drawn upon to focus on the overall implementation effectiveness, technical validity, and functioning of the DD formula-grant program in relation to overall program goals. The participant planners' perceptions, in combination with other relevant information, are the basis for consideration of the two research concerns of (a) whether the DD program has been sucessful in achieving its planning-related goals, and (b) why or why not, i.e., under what other circumstances, if any, could the DD program be more successful in achieving these planning-related goals.