The clinical syndrome of Huntington’s disease is notable for a triad of motor, cognitive and emotional features. All HD patients eventually become occupationally disabled; however the factors that render HD patients unable to maintain employment have not been extensively studied. This review begins by discussing the clinical triad of HD, highlighting the distinction in the motor disorder between involuntary movements such as chorea, and voluntary movement impairment, with the latter contributing more to functional disability. Cognitive disorder clearly contributes to disability, though the relative contribution compared to motor is difficult to unravel, especially since many of the tests used to asses “cognition” have a strong motor component. The role of emotional changes in disability needs more study. The literature on contributions to functional disability, driving impairment and nursing home placement is reviewed. Relevant experience is presented from the longstanding JHU HD observational study on motor vs cognitive onset, and on cognitive and motor features at the time when individuals discontinued working. Finally, we briefly review government policies in several countries on disability determination. We interpret the data from our own studies and from the literature to indicate that there is usually a close relationship between cognitive and motor dysfunction, and that it is critical to take both into consideration in determining disability.