Operational conditions, including humidity, exposure to atmosphere air, sea spray, and exhaust, can leave Navy surface ships susceptible to fungal growth, which can lead to a health stressor for the ships’ force, and unaesthetic conditions for paint and coatings. Additionally, fungal growth has been shown to feed on the resins, fillers, and plasticizers found in coatings, which could lead to degradation of coating performance over time, and occurrence of corrosion. While current interior coatings such as MIL-PRF-24596 include a mold-resistant performance requirement in accordance with ASTM D3274, no mold-inhibitive coating has been developed for Navy use.1 However, Environmental Security Technology Certification Program (ESTCP) has funded Naval Surface Warfare Center, Carderock Division (NSWCCD), Navy Research Laboratory Stennis Space Center (NRLSSC), and industry partners to develop a mold-inhibiting coating from MIL-PRF-24596 Navy interior coatings. Mold and coating samples were collected from 27 ships across seven geographic locations for DNA analysis and identification. These mold samples were analyzed to determine the most common species and highlight those that are toxigenic. Mold-inhibitive additives were identified and formulated into a qualified MIL-PRF-24596 coating for ship demonstration in 2023.2