By describing what has been learned in disseminating Success for All, a reform program for high-poverty elementary schools, this paper explores how a national approach to professional development might enable professional development networks to implement proven school change models. Success for All restructures the elementary school by emphasizing prevention; early intervention; use of innovative reading, writing, and language arts curricula; and extensive professional development. Research in 17 schools in 7 districts has shown the positive effects of Success for All on increasing reading achievement, reducing retentions, improving attendance, and reducing special education placements. Examining its dissemination from its first appearance in one Baltimore (Maryland) school in 1987-88 through its expansion to about 200 schools nationwide in 1994-95 demonstrates the necessity of a skilled staff of trainers to work with schools. Mentoring and apprenticeships for teachers are among the strategies that make dissemination successful. Participating network schools and the central training staff are the keys to scaling up the Success for All program. (Contains 1 table and 14 references.) (SLD)