Early identification of persons with chronic HBV infection enables infected persons to receive necessary care to prevent or delay onset of liver disease, and enables the identification and vaccination of susceptible household contacts and sex partners, interrupting ongoing transmission. Testing has been recommended previously to enable primary prevention of HBV infection among close contacts for pregnant women, household contacts and sex partners of HBV-infected persons, persons born in countries with hepatitis B surface antigen (HBsAg) prevalence of more than 8%, persons who are the source of blood or body fluid exposures that might warrant postexposure prophylaxis (e.g., needlestick injury to a healthcare worker or sexual assault), and to enable appropriate treatment for infants born to HBsAg-positive mothers and persons infected with human immunodeficiency virus. Recently, with the increasing availability of efficacious hepatitis B treatment, the Centers for Disease Control and Prevention published new recommendations for public health evaluation and management for chronically infected persons and their contacts and extended testing recommendations to include persons born in geographic regions with HBsAg prevalence of greater than 2%, men who have sex with men, and injection drug users. Patient and provider education, developing partnerships between health departments and community organizations, and other resources will be needed to assure appropriate populations are tested and care provided for persons newly identified as HBsAg-positive. (HEPATOLOGY 2009;49:S35–S44.)