Purpose: To describe patterns of care use for Alabama Medicaid adult beneficiaries with diabetes and the association between primary care utilization and ambulatory care sensitive (ACS) diabetes hospitalizations. Methods: This retrospective cohort study analyzes Alabama Medicaid claims data from January 2010 to April 2018 for 52,549 covered adults ages 19–64 with diabetes. Individuals were characterized by demographics, comorbidities, and health care use including primary, specialty, mental health and hospital care. Characteristics of those with and without any ACS diabetes hospitalization are reported. A set of 118,758 observations was created, pairing information on primary care use in one year with ACS hospitalizations in the following year. Logistic regression analysis was used to assess the impact of primary care use on the occurrence of an ACS hospitalization. Results: One third of the cohort had at least one ACS diabetes hospitalization over their observed periods; hospital users tended to have multiple ACS hospitalizations. Hospital users had more comorbidities and pharmaceutical and other types of care use than those with no ACS hospitalizations. Controlling for other types of care use, comorbidities and demographics, having a primary care visit in one year was significantly associated with a reduced likelihood of ACS hospitalization in the following year (odds ratio comparing 1–2 visits versus none 0.79, 95% confidence interval 0.73–0.85). Conclusions: Program and population health interventions that increase access to primary care can have a beneficial effect of reducing excess inpatient hospital use for Medicaid covered adults with diabetes.