This study examined schools which had successfully blended gifted education programs into middle school environments in order to provide outstanding services to gifted middle grades students, and sought to determine the factors that made this successful blending possible. Five sites were visited from a variety of settings and schools that used various service delivery models. The five specific sites included: (1) Brewster Middle School (North Carolina); (2) Wilson Middle School (Oklahoma); (3) Western Middle School (North Carolina); (4) Burbank Middle School (Michigan); and (5) Meads Mill Middle School (Michigan). Factors that were found to be critical or important to program effectiveness at all five sites included: school site administrators who demonstrated a clear commitment to the middle school philosophy and provided a challenging environment for all students, autonomy of principals and teachers, availability of expertise and human resources, enthusiasm of students and teachers, a sense of trust and commitment to the school, and curriculum differentiation which used some form of instructional (ability/performance) grouping and enrichment. Schools used a variety of service delivery models, including pull out classes, separate classes, and team clusters. The one common element was that students were grouped by ability and/or performance for language arts and mathematics instruction. The study concluded that it is possible to blend appropriately differentiated services for gifted students into schools operating within an authentic middle school paradigm. (Contains 24 references.) (JDD)