Limited data exist on whether structural factors associated with poverty such as inadequate housing and food insecurity affect diabetes care. In a sample of low-income participants with diabetes (N=711), we sought to determine if housing instability was associated with lower diabetes self-efficacy, and whether this relationship was mediated by food insecurity. We ordered housing from most to least stable. We observed a linear decrease in diabetes self-efficacy as housing instability increased (p<.01). After adjusting for age, sex, race/ethnicity, and alcohol or substance use, adults lacking a usual place to stay had lower self-efficacy than those who owned their own home (ß-coefficient -0.94, 95% CI -1.88, -0.01). Food insecurity mediated the association between housing instability and diabetes self-efficacy (ß-coefficient -0.64, 95% CI -1.57, 0.31). Our findings suggest that inadequate access to food lowers self-efficacy among adults with diabetes, and supports provision of food to unstably housed adults as part of diabetes care.