The purpose of this paper was to summarize the implementation of a schoolwide tiered intervention program in three Midwestern U.S. elementary schools over a period of three years. The program, Social Skills Training and Aggression Reduction Techniques plus Time-Away (START[superscript Plus]) includes components of social skills training at the universal primary level, small group instruction at the targeted level, and individualized, intensive intervention in problem-solving and conflict resolution at the tertiary level. The effectiveness of the tiered program was assessed through measures of attendance, frequency of Time-Away referrals, frequency of disciplinary referrals, and levels of academic achievement. Results indicated significant increases in attendance, reductions in Time-Away and disciplinary referrals, and mixed results in academic achievement scores. Informal survey and anecdotal data indicated changes in the climate of the school. Implications for future research and limitations are included.