Primary biliary cirrhosis is an insidious disease that progresses through the clinical phases: preclinical, asymptomatic, symptomatic, and liver insufficiency. The outlook of patients diagnosed with PBC has improved significantly over the past 2 decades because more patients are being diagnosed earlier in the disease process and being treated with UDCA. A need remains to better define and predict the course of symptomatic and asymptomatic patients on and off UDCA in order to better evaluate outcomes of clinical trials.