© 2019 Association of Military Surgeons of the United States 2019. All rights reserved.Excessive alcohol consumption continues to be a significant concern to overall military readiness; each year, it results in non-deployable active duty service members and service members separated from service. In 2009, The Community Preventive Services Task Force recommended limiting the hours of alcohol sales as an evidence-based and effective intervention to reduce alcohol-related harms. In June 2014, partnerships at an Army Installation in the Midwestern United States implemented a policy to reduce excessive alcohol consumption and associated alcohol-related harms. Although community-based interventions have been shown to successfully reduce alcohol-related negative consequences, little research has explored the effects of these interventions in military communities. Materials and Methods: The intervention reduced the retail sale of alcoholic beverages by eight hours daily (11:01 pm to 6:59 am) within the installation community. The U.S. Army Public Health Review Board approved this study as public health practice. The quantitative assessment from a mixed-methods evaluation implemented an interrupted time series design to assess changes in the community resulting from the intervention. Revenue and crime data were collected 11 months and 12 months prior to and after the onset of the intervention, respectively, to quantify the adherence to and effectiveness of the policy. The outcome variables measured in the evaluation were Serious Incident Reports (SIRs) and Driving Under the Influence/Driving While Intoxicated (DUI/DWI) citations. A Wilcoxon Signed-Rank Test of significance was used to measure changes in crime outcomes post-policy. Results: The results indicated that pre-policy rates of overall DUI/DWI citations, and DUI/DWI citations on-post were significantly higher than post-policy DUI/DWI citations (p < 0.05). The results also indicated that pre-policy rates of overall SIRS, alcohol-related SIRs, and SIRs occurring at night were not statistically higher than post-policy rates (p ≥ 0.05). The pre-policy DUI/DWI citations occurring off-post and DUI/DWI citations occurring at night did not reach statistical significance (p > 0.05). Policy adherence was good and total alcohol sales revenue remained stable before and after policy implementation. Conclusions: This was the first known evaluation within a military community to report improvements in crime statistics following an eight hour reduction in daily retail sale hours of alcohol. The reduction in alcohol-related harms presented in this evaluation are typical for small communities implementing alcohol-related policies; however, the effect sizes reported here are larger than those reported in the current literature, suggesting that the policy positively impacted the installation community in decreasing alcohol-related harms. Evaluation data did not show statistically significant reductions in DUI/DWI citations and SIRs occurring during night hours. Further, the evaluation design disallows the ability to draw a causal relationship between the intervention and measured outcomes. Additional installations should consider implementing similar policies to determine if observed effects are replicable. Future studies should include a longitudinal design that would allow for long-lasting changes to be observed within the population, measurement of additional proximal outcomes (e.g., reported alcohol consumption), and investigating social and health outcomes both inside and outside the confines of the installation community.