This report updates the 1991 CDC recommendations for the management of hepatitis B virus (HBV)-infected health-care providers and students to reduce risk for transmitting HBV to patients during the conduct of exposure-prone invasive procedures (CDC. Recommendations for preventing transmission of human immunodeficiency virus and hepatitis B virus to patients during exposure-prone invasive procedures. MMWR 1991;40[No. RR-8]). This update reflects changes in the epidemiology of HBV infection in the United States and advances in the medical management of chronic HBV infection and policy directives issued by health authorities since 1991. The primary goal of this report is to promote patient safety while providing risk management and practice guidance to HBV-infected health-care providers and students, particularly those performing exposure-prone procedures such as certain types of surgery. Because percutaneous injuries sustained by health-care personnel during certain surgical, obstetrical, and dental procedures provide a potential route of HBV transmission to patients as well as providers, this report emphasizes prevention of operator injuries and blood exposures during exposure-prone surgical, obstetrical, and dental procedures. These updated recommendations reaffirm the 1991 CDC recommendation that HBV infection alone should not disqualify infected persons from the practice or study of surgery, dentistry, medicine, or allied health fields. The previous recommendations have been updated to include the following changes: no prenotification of patients of a health-care provider's or student's HBV status; use of HBV DNA serum levels rather than hepatitis B e-antigen status to monitor infectivity; and, for those health-care professionals requiring oversight, specific suggestions for composition of expert review panels and threshold value of serum HBV DNA considered "safe" for practice (<1,000 IU/ml). These recommendations also explicitly address the issue of medical and dental students who are discovered to have chronic HBV infection. For most chronically HBV-infected providers and students who conform to current standards for infection control, HBV infection status alone does not require any curtailing of their practices or supervised learning experiences. These updated recommendations outline the criteria for safe clinical practice of HBV-infected providers and students that can be used by the appropriate occupational or student health authorities to develop their own institutional policies. These recommendations also can be used by an institutional expert panel that monitors providers who perform exposure-prone procedures.