Noncontingent reinforcement (NCR) is an effective behavioral intervention when implemented consistently. NCR may be particularly well-suited for use in schools because of its perceived ease of use. However, previous laboratory research suggests that NCR may not maintain therapeutic effects if implemented inconsistently. Inconsistent implementation (i.e., implementation with integrity errors) is likely when teachers are expected to implement NCR alongside many other responsibilities. The purpose of this experiment was to assess the efficacy of NCR with integrity errors for students with disruptive behavior in a school setting. We evaluated NCR with errors of commission (reinforcers contingent on challenging behavior) and errors of omission (omitted response-independent reinforcers). At least one error type was detrimental for each participant. These results, in conjunction with previous findings, suggest that NCR should be implemented with high integrity to remain consistently effective. Suggestions for the use of NCR in schools are provided.