Military healthcare providers working with Traumatic Brain Injury (TBI) patients, face numerous challenges as they help soldiers reintegrate into society. Perhaps the biggest ethical challenge these providers face is the question of how much capacity their patients have when it comes to making choices about care. In other words, can the patient properly give informed consent for a given treatment option and then make an informed decision? For TBI military patients, inherent to capacity are two issues: 1) autonomy verses paternalism and 2) consent verses assent. These issues raise two difficult questions. First, how much autonomy does the TBI patient have and how much paternalism should a provider exercise or exercise it at all? Second, in TBI adults with diminished capacity, is informed consent necessary or is assent good enough and does it matter if they are state side or in a theater of operations? In considering each of these ethical questions from a military point of view, we have found that a degree of paternalism is permissible with TBI patients. TBI clinical experience suggests that the amount of paternalism required for a given case is inversely proportional to the amount of capacity possessed by the individual. Furthermore, while it is good clinical practice to make sure that patients are informed about their healthcare choices, informed consent is not always possible with military TBI patients. In such situations, the military steps in as a surrogate decision maker for the TBI patient and orders treatment. Due to states interest of preserving life and restoring function, it is ethically permissible to settle for assent. In this case, TBI clinical experience suggests that a good clinical outcome can only occur if the patient at least assents to treatment.