This serial contains CDC guidance that augments the 2011 recommendations of the Advisory Committee on Immunization Practices (ACIP) for evaluating hepatitis B protection among health-care personnel (HCP) and administering post-exposure prophylaxis. Although the rate of acute hepatitis B virus (HBV) infections have declined approximately 89% during 1990–2011, from 8.5 to 0.9 cases per 100,000 population in the United States, the risk for occupationally acquired HBV among HCP persists, largely from exposures to patients with chronic HBV infection.