In this study, the authors explore the implementation of a statewide class-size reduction program in nine high-poverty schools. Through qualitative methods, they examined how schools used class-size reduction to change staffing patterns and instructional programs. Requiring changes in space allocation, class-size reduction was accomplished through attention to pupil:teacher ratio, with classes ranging from 15:1 to 30:2 team taught. Most partner classes used tag-team teaching, with one teacher leading and the other doing clerical work. Working without specific professional development to enhance teaching in smaller classes, it made sense that teachers continued to solo practice. Class-size reduction is both a programmatic and instructional reform, and as such, it requires specific professional development to promote change. (Contains 3 tables and 3 notes.)