OBJECTIVES: To compare the health care costs of acute urinary tract infections (UTIs) and genital infections (GIs) between adults with type 2 diabetes mellitus (T2DM) versus those without DM (no-DM). METHODS: Using administrative claims data and a retrospective cohort design, commercially-insured adults with UTIs (cystitis or urethritis) or GIs (vulvovaginal candidiasis, bacterial vaginosis, or balanitis) from 2006-2010 were selected. The first UTI or GI event after a 6-month continuous enrollment period was identified, with the event date as the index date. T2DM patients, identified by ICD-9 diagnosis codes and use of non-insulin, anti-diabetic medications, were matched with a 1:3 ratio to no-DM patients on gender, age group, index year, and recurrence status ( ≥2 events) in the 6-month pre-index period. Health care costs related to UTI and GI events in the 30-day post-index period were compared between T2DM and no-DM cohorts. RESULTS: Matched UTI cohorts included 314,390 males (mean age: 59) and 944,749 females (mean age: 57). Total health care costs (mean ± standard error) related to UTIs were higher for T2DM than no-DM among males ($569±13 vs. $412±5) and females ($437±5 vs. $303±2). Inpatient and outpatient costs related to UTIs were also higher for T2DM than no-DM among males ($265±11 vs. $148±4; $221±5 vs. $189±2) and females ($163±4 vs. $88±2; $190±2 vs. $152±1), respectively. Matched GI cohorts included 23,853 males (mean age: 53) and 336,932 females (mean age: 50). Total health care costs related to GIs were higher for T2DM than no-DM among males ($457±30 vs. $332±14) and females ($181±6 vs. $133±1). The same pattern was observed for GI-related inpatient and outpatient costs. All cost differences between T2DM and no-DM were statistically significant (p<0.05 by Wilcoxon rank-sum test). CONCLUSIONS: Relative to non-diabetics with urogenital conditions, the costs of T2DM patients with urogenital conditions were significantly higher.