DOD and NATO policy direct active-duty service members (ADSM) to possess accurate military identification tags (MITs) and medical warning tags (MWTs) to mitigate the risk of life-threatening transfusion and allergic reactions in resource constrained deployed environments. Studies to evaluate blood type discrepancies on MITs have not been conducted in the 21st century, and the few studies in the 1980s and 1990s demonstrated ABO/Rh mismatch rates ranging from 3-15%. To date, there have never been studies evaluating MWT prevalence among ADSM. This study aims to be the first in both respects, given the updates to the electronic health record (EHR) and general advances in technology. This is a cross-sectional analytical study that utilized record review to compare blood types and documented allergies in the military EHR to the information on the MITs and MWTs of ADSM. ADSMs were surveyed about active possession of MITs/MWTs as well as about their allergy histories. Their respective medical officers collected data from study participants’ MITs and MWTs regarding blood type and allergy. The primary research team compared the collected data to what was present in the ADSM’s EHR. The resulting data was analyzed via descriptive statistics. A total of 966 ADSM were surveyed across the Navy and Marine Corps. The prevalence of MITs among ADSM was 57%. Among those who had MITs, the rate of ABO or Rh error was 5.2%. The prevalence of severe allergy via report or EHR documentation was 10.7%. Of the 104 ADSM with reported or documented allergies, MWT prevalence was 42.3%. When the allergy was solely reported but not documented in the EHR, MWT prevalence was 8.3%. When the allergy was not reported but solely documented in the EHR, MWT prevalence was 40.6%. When the allergy was both reported and documented in EHR, MWT prevalence was 50.0%. Despite improvements in medical reporting technology, the prevalence of ABO/Rh errors on MITs is 5%, and the issuance of required MWTs for ADSMs with allergies is inconsistent and far below standards. Inaccurate blood type and allergy reporting on MITs/MWTs increases the risk of preventable life-threatening transfusion and allergic reactions in forward deployed military populations. Furthermore, MWT issuance is a key component in medical readiness as it is a standard question on periodic health assessments. Ensuring accurate and proper dissemination of MITs and MWTs is paramount to ensuring that warfighters are fully medically ready for deployment. Next steps to improve the accuracy of blood typing on MITs and the prevalence of MWTs will require significant process improvement. At the MTF level, ADSM stationed at Naval Medical Center Portsmouth are responsible for presenting to the Norfolk NEX and entering MWT information without medical officer oversight. For MIT issuance, ADSM are responsible for providing their blood type to the Plans, Operations, and Medical Intelligence office without EHR confirmation or medical officer oversight. The next steps of this project look to initiate changes at the MTF level and assess subsequent MIT accuracy and MWT prevalence and may involve standardized forms and medical officer oversight.