OBJECTIVES: Understanding associations between care organization and ambulatory care sensitive bacterial pneumonia hospitalizations (A-BPHs) is important for outcomes management and has important policy implications.  We determined rates of A-BPH among Medicaid beneficiaries and assessed association between care organization and A-BPH. METHODS: A retrospective cohort analysis of Medicaid claims, enrollment, and encounter data was conducted.  Sample inclusion criteria were ≥ 18 y/o, and continuous eligibility in 2008.  Exclusion criteria were a nursing home stay, no claims, or dying in 2008.  A-BPHs were identified based on AHRQ prevention quality indicator specifications for bacterial pneumonia.  Each individual was placed in one of four groups based on whether continuously enrolled in Fee for Service (FFS), Care Management (CM), or Managed care (MC) subprograms; or whether switches between subprograms occurred in 2008.  Persons enrolled in CM entered through disability determination, while other groups had no known disability indication.  Logistic regression assessed association between care organization and A-BPH adjusting for age, gender, ethnicity, Charlson comorbidity, state Medicaid region, and history of coronary heart disease, cerebrovascular accident, congestive heart failure, claudication, chronic obstructive pulmonary disease, or diabetes mellitus in the 12 months prior to the study period. RESULTS: A sample of 197,964 persons, with a mean age of 43 years, 70% female, and 75% white was identified.  Overall, 1,726 A-BPHs occurred, a rate of 872 per 100,000 persons.  Although no significant difference was seen between individuals in CM or individuals who switched subprograms as compared to individuals in FFS, individuals enrolled in MC were less likely to have A-BPHs as compared to those in FFS (Odds ratio = 0.38, 95% CI = 0.29 – 0.50, P <0.0001) after adjusting for covariates. CONCLUSIONS: Enrollment in Managed Care was associated with lower likelihood of ambulatory care sensitive bacterial pneumonia hospitalization even after adjusting for risk factors.