The primary function of the Royal Centre for Defence Medicine (RCDM) is to provide medical support to military operational deployments. It also provides secondary and specialist care for members of the armed forces. It is a dedicated training centre for defence personnel and a focus for medical research. The RCDM is a tri-service establishment, meaning that there are personnel from all three of the armed services. The military staff wear their own distinctive uniforms that vary depending on whether they are serving with the Navy, Army, or Air Force (although some wear a generic green uniform, with rank insignia, depending on the area in which they work). The RCDM is based at the new Queen Elizabeth Hospital Birmingham, with defence personnel fully integrated with NHS staff to treat both military and civilian patients. The Trust also holds the contract for providing medical services to military personnel evacuated from overseas via the “Aero med service”.