Objective: The U.S. Air Force recently implemented system-wide changes that both (a) clarified the criteria used to determine when family maltreatment has occurred and (b) made the process by which these decisions are made more consistent. The current study examined the effects of these changes on family maltreatment recidivism. Method: Official records were obtained from the Air Force Family Advocacy Program. All cases decided during the last year of the old system and the first year of the new system at each base (total N = 14,298) were examined. For each incident, it was determined (a) whether the incident met criteria and (b) whether the same offender committed family maltreatment again within 1 year of the initial incident. Results: Overall substantiation rates were significantly lower (p = .003) under the new system (47%) than the old (56%). After the change, significant interaction effects were obtained for both alleged (b = −.51, p = .004) and substantiated (b = −.55, p = .015) reoffense, in that 1-year reoffense rates decreased significantly among initially substantiated cases but remained unchanged among initially unsubstantiated cases. Indeed, rates of substantiated reoffense by substantiated offenders were cut in half (from 14% to 7%). Conclusions: Reductions in overall substantiation rates were most likely due to the use of more stringent criteria. The results of the recidivism analyses suggest that clear criteria and consistent decision processes can have secondary preventive effects on family maltreatment in their own right, possibly due to increases in informal community sanctions.