Responding to a written parliamentary question from Helen Maguire MP, Minister for Veterans and People Louise Sandher-Jones provided figures showing that as of 1 September 2025, there were 13,113 service personnel classified as Medically Not Deployable (MND). Of these, 12,399 had conditions coded under the International Classification of Diseases (ICD-10) system.
Musculoskeletal disorders and injuries accounted for 43% of cases, while mental and behavioural disorders made up 22%, according to the data. Other significant categories included factors influencing health status (7%), ill-defined clinical and laboratory findings (4%), and digestive system disorders (3%).
Smaller proportions of non-deployable personnel were affected by conditions related to the ear and mastoid process, circulatory system, neoplasms, metabolic and endocrine disorders, and nervous system issues. Conditions such as respiratory, skin, and genitourinary diseases each represented around 1% or less of cases.
The data also showed that 321 cases could not be coded under ICD-10, and 393 had no medical board information available.
The Ministry of Defence explained that personnel classified as Medically Not Deployable are deemed unfit for operational deployment but may still participate in UK-based exercises. The department noted that some of those listed as MND on the reporting date "may not have been scheduled to deploy and the medical condition may not have prevented deployment."
The figures cover all full-time trained Royal Navy and RAF personnel and trade-trained Army personnel serving against requirement as of September 2025.
According to the Ministry of Defence, the medical downgrading data was compiled from the Defence Medical Information Capability Programme (DMICP) and converted into ICD-10 codes for reporting purposes. The department added that the "clinical and laboratory findings" category includes symptoms such as irregular heartbeat or abdominal pain that may lack a formal diagnosis.