The Naval Infectious Diseases Diagnostic Laboratory (NIDDL) is a College of American Pathologists (CAP)-accredited, Clinical Laboratory Improvement Program (CLIP)-certified reference clinical diagnostic laboratory within the Department of Defense (DoD). It was established in 2010 with the mission to provide world-class infectious disease diagnostic testing services for military health system (MHS) beneficiaries, provide reach back support, and conduct surveillance effort for the DoD. Since then, the NIDDL has played an active role in responding to disease outbreaks, such as the Zika pandemic, COVID-19 pandemic, and mpox outbreak through both clinical diagnostic tests and research. Through its national membership with the Laboratory Response Network (LRN), the laboratory continuously strives to add more testing capabilities to answer the need of the DoD and also conduct surveillance effort for diseases of military importance. As part of research and surveillance, the NIDDL actively developed and evaluated new diagnostic tests and conducted a Lyme serosurveillance study in returning personnel from Honduras. It has also provided support to internal and external collaborators in epidemiological studies such as the COVID-19 Health Action Response for Marines (CHARM) and the Leptospirosis risk during Jungle Warfare training. In summary, the NIDDL is a unique member within the MHS through its capability to provide dual functions in clinical and research realms of military medicine. Disclaimer: SAJ is a military service member. This work was prepared as part of their official duties. Title 17, U.S.C., §105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S.C., §101 defines a U.S. Government work as a work prepared by a military Service member or employee of the U.S. Government as part of that person’s official duties. The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the U.S. Navy, the Department of Defense, the U.S. government, or the institutions affiliated with the authors. Authors declared no conflict of interest. The NIDDL was supported by Navy BUMED Operations and Maintenance funds.