Urinary tract infections (UTIs) are one of the most commonly diagnosed infections, and prior studies have reported discordance in antibiotic treatment with the Infectious Diseases Society of America (IDSA) guidelines. To assess IDSA guideline concordance rates for women with uncomplicated UTIs treated with antibiotics, and compare concordance rates between different specialty field. Retrospective cross-sectional study of health care claims data from the US Military Health System Data Repository, which contains comprehensive health care encounter and claims data for all military beneficiaries. Participants were adult women between the ages of 18 to 50 years with uncomplicated UTIs from October 1, 2017, to September 30, 2019. Data extraction and analysis were performed in 2022. Patients with diagnosis of UTI in the preceding 6 months, current pregnancy, history of pyelonephritis, history of diabetes, history of organ transplant, history of human immunodeficiency virus, immunosuppression, renal insufficiency, urinary tract abnormalities, or history of urologic procedures were excluded. Antibiotic treatment for uncomplicated UTIs. Only antibiotics received within 1 day after the diagnosis were analyzed. The IDSA recommends the following antibiotics as first-line therapy: nitrofurantoin, trimethoprim-sulfamethoxazole, fosfomycin, pivmecillinam. The IDSA guideline concordance rates were calculated as the number of patients receiving first-line antibiotic therapy divided by the total number of cases for uncomplicated UTIs. A total of 46 793 adult women (67.3% [31 475 of 46 793] aged 18-34 years; 38.2% [31 475 of 46 793] of White race) were diagnosed with uncomplicated UTIs with 91.0% receiving guideline-concordant antibiotic treatment. In comparison with obstetrics and gynecology, IDSA guideline-concordant treatment was more likely in internal medicine (adjusted odds ratio [aOR], 2.87; 95% CI, 2.73-3.03), family medicine (aOR, 1.81; 95% CI, 1.76-1.87), surgery (aOR, 1.51; 95% CI, 1.36-1.67), and emergency medicine (aOR, 1.36; 95% CI, 1.32-1.39) and less likely in urology (aOR, 0.40; 95% CI, 0.38-0.43). Compared with direct military care, private sector care had lower concordance rates (aOR, 0.63; 95% CI, 0.62-0.64). In this cross-sectional study of antibiotic treatments for uncomplicated UTIs in a universally insured population, the IDSA guideline-concordance rate was high at 91.0% with higher rates in direct military care compared with private sector care. There were higher rates in general medical specialties, surgery, and emergency medicine and lower rates in urology and obstetrics and gynecology. These results further enhance the literature on current antibiotic prescribing practices for uncomplicated UTIs in adult women.