maintain active board certification by taking a re-certification exam every 10 years. specialty pays incentivize the various specialties and sub-specialties with sliding rates and a variety of contracts (generally 2, 3, or 4 years) are available after any basic educational obligation has been fulfilled. career assignment fields u.s. army physicians serve in one of three general career fields that are not formal parts of the mos classification system: operational medicine is the field of army medicine that provides medical support to the soldier and his/her chain of command. many operational physicians serve as division, brigade and battalion level surgeons (the word "surgeon" is used to identify a physician that is assigned to a unit as a primary care provider and not necessarily as a general surgeon). these physicians are either assigned through the profis (professional filler system) or through permanent assignment (pcs). deployments with units to combat theaters are for the duration of a deployment and the jobs are mostly filled by primary care physicians. a profis provider can expect to be deployed away from their family for a total of 16 months (1 month before deployment, 12 months in theater, and 3 months for "stabilization" after return to the assigned units home station). this means that primary care physicians are deployed for longer periods than most specialist physicians. a specialist (ie..general surgeon, trauma surgeon, rheumatologist) will usually be deployed for 6 months. operational physicians should expect that greater than 60% of their time will be spent in administrative roles and non-patient care. 40% of the operational providers time is spent caring for soldiers or supervising unit physician assistants(pas). with the recent bct (brigade combat team) restructuring, the demand for operational surgeons have increased. likely, the poor retention of captains and junior major physicians in the primary care fields is due to the relative inequality of deployment length and deployment frequency. clinical medicine is the field of army medicine where a physician in uniform basically functions like a physician in the civilian arena. these physicians are assigned to the various army medcens (medical centers) and meddacs (medical department activities, i.e., hospitals and clinics). each of these physicians are assigned to a profis unit. usually primary care physicians deploy to fill battalion level surgeon positions. medical specialists deploy to support csh (combat support hospitals). research medicine is filled by the minority of military physicians. most of these research physicians are based in larger army medical centers.