The traditional view that individuals carrying an expanded Huntington’s disease (HD) gene undergo phenoconversion, a stochastic event that takes them from symptom-free to symptomatic, is now disputed among clinicians, HD researchers, and patient and family advocates. Disease onset is officially declared when neurologic abnormalities that are unequivocally due to HD are diagnosed, but subjective symptoms and objective signs emerge gradually, and it is more helpful to consider and openly discuss a prodromal period, often as long as 10 years, which can provide a helpful framework for discussion and management. Considerable progress has been made in defining the neurobiologic processes that underlie the development of HD in humans and measures that can predict this for the purpose of conducting clinical trials, but these measures have not yet been validated sufficiently to make them useful in the clinical setting. This chapter discusses the multidisciplinary care of patients with premanifest, prodromal, and early manifest HD.