A group of nine elementary school children, each referred originally by his/her teacher due to low levels of peer interaction in free-play situations at school, participated in a study designed to assess the effects of treatment "booster shots" on the maintenance of social behavior. Five of the children had been treated previously for social withdrawal; the other four had not. An intervention package, consisting of social skills tutoring and a recess-based point system, was alternated with treatment reversal periods to determine whether maintenance effects would accumulate with repeated exposure to treatment procedures. Observational data collected during playground recess periods showed that four of the five previously treated subjects were interacting within normative levels of social behavior following a series of three treatment "booster shots." Only one of the four previously untreated subjects showed evidence of a similar effect. Results indicate that a treatment "booster shot" strategy might provide an effective means of facilitating maintenance of interactive behavior for children previously treated for social withdrawal. (Author)