Background The burden of emerging tick and flea-borne disease in the United States (US) is increasing, but the true prevalence remains undefined. Given the military’s frequent field training, these infections have a potential impact on force readiness. Studies evaluating more diverse geographic ranges within the US remain to be conducted, particularly in the military. Here, the Defense Medical Surveillance System (DMSS)—an archive of all clinical data of the DOD serum repository—is evaluated for prevalence and characteristics of various rickettsial diseases diagnosed within the military system. Methods A retrospective descriptive study of epidemiological data in the DMSS was performed. The DMSS was queried for all confirmed and suspected cases of Murine Typhus (MT), Spotted Fever (SF), Ehrlichiosis/Anaplasmosis (A/E) and Babesiosis (BA) between 1994 and 2024. Confirmed cases were defined as one record of a reportable medical event with laboratory confirmation and suspected cases were defined as one inpatient or 2 outpatient encounters, with a disease-associated ICD-code. Laboratory data was available from 2007 onwards. Results Overall, 1902 cases of SF (since 1994), 636 cases of MT (since 1995), 140 cases of BA (since 2005), and 392 cases of A/E (since 1996) were identified. 60-84% of cases met the criteria for confirmed disease via lab positivity or as a reportable medical event. There were significant increases in BA, SF and MT across the decades of 1995-2005, 2006-2015, 2016-2024. When comparing 2006-2015 to 2016-2024, mean cases of BA nearly quadrupled (3.2 to 11.8 cases/year). Between 1996-2005 and 2016-2024, SF increased ten-fold (11.5 to 126.6 cases/year) and MT quadrupled (1.6 cases to 43.8 cases/year). A/E incidence peaked in 2006-2015 with 22 cases/year. The top 5 states made up roughly 50% of all cases for an individual disease, with North Carolina, Missouri and Virginia representing significant proportions of rickettsial infection. Occupational codes associated with heavy field exposure, such as artillery and infantry, were correlated with more cases. White, male and age <35 was associated with more diagnoses, but generally reflected known military demographic biases. Discussion This inquiry into the DMSS data confirms several aspects of these diseases—most notably their year-over-year increases. The data also supports that a minority of states with most cases present an opportunity for further study and focused intervention. While BA, A/E and SF are nationally reportable diseases, MT is not, which makes this data useful, in that it suggests there is potentially under-recognized burden in states such as Missouri. Understanding the changing geographic distribution of these diseases is paramount as vectors expand their home ranges.