The ethical principle of autonomy requires physicians to respect patient autonomy when present, and to protect the patient who lacks autonomy. Fulfilling this ethical obligation when a patient has a communication impairment presents considerable challenges. Standard methods for evaluating decision-making capacity require a semistructured interview. Some patients with communication impairments are unable to engage in a semistructured interview and are at risk of the wrongful loss of autonomy. In this article, we present a general strategy for assessing decision-making capacity in patients with communication impairments. We derive this strategy by reflecting on a particular case. The strategy involves three steps: (1) determining the reliability of communication, (2) widening the bandwidth of communication, and (3) using compensatory measures of decision-making capacity. We argue that this strategy may be useful for assessing decision-making capacity and preserving autonomy in some patients with communication impairments.