Abstract: Background: Despite universal coverage of all highly effective contraceptive (HEC) methods in the Military Health System (MHS), active duty service women (ADSW) have higher rates of unintended pregnancy and lower rates of HEC use than the general U.S. population. Between 2016 and 2019, racial minority and lower socioeconomic status (SES) ADSW demonstrated lower odds of HEC use. This study further investigated factors associated with HEC use among ADSW to assess their reproductive health needs. Methods: We conducted a cross-sectional study using fiscal year 2020-2023 data from the MHS Data Repository for all ADSW aged 18-45 years. Statistical analyses included descriptive statistics and logistic regression models, adjusted and unadjusted, determining the odds of HEC use overall, by method, and by social characteristics, including race and military rank as a proxy for SES. Results: Of the 339,011 ADSW identified, 164,756 (48.6%) used at least one HEC method during the study period. Black (odds ratio [OR] = 0.89; 95% confidence interval [CI] = 0.88-0.91) and Asian/Pacific Islander (OR = 0.88; 95% CI = 0.78-0.82) ADSW demonstrated lower odds of overall HEC use than White ADSW. Junior Enlisted ADSW demonstrated lower odds of overall HEC use than nearly all other ranks. Conclusions: The proportion of ADSW using HEC methods has decreased since 2019, while HEC use in the general population has increased. Racial and socioeconomic disparities remain, highlighting the need for future research to investigate reasons for these disparities in order to design effective mitigation strategies to ensure access to contraceptive care for all ADSW.