Hepatitis B virus (HBV) remains an important cause of acute and chronic liver disease globally and in the United States. An encouraging trend is that the incidence of acute hepatitis B in the United States declined as much as 80% between 1987 and 2004, attributable to effective vaccination programs as well as universal precautions in needle use and in healthcare in general. Although encouraging, these decreases in acute infections have not translated into diminished prevalence or burden of chronic HBV infection. The prevalence for HBV in the United States has been estimated to be approximately 0.4%. However, these estimates have been based on surveys conducted in samples in which population groups with high prevalence of HBV infection, namely foreign-born minorities, were underrepresented. Voluntary screening data indicate prevalence in excess of 15% in some of these groups. Recent immigration trends suggest a substantial increase in the number of Americans with chronic HBV infection. This trend is reflected in the health and economic burden associated with HBV infection. The number of outpatient visits and hospitalizations for a HBV-related diagnosis increased several-fold during the 1990s. Similarly, the total charges for hospitalizations have been estimated to have increased from $357 million in 1990 to $1.5 billion in 2003. Most recent data indicate that death and liver transplant waitlist registration for HBV-related liver disease, which had been increasing, have now reached a plateau or started to decline. This encouraging trend might be attributable to recent advances in treatment for HBV infection; however, to the extent that the number of Americans living with chronic HBV is growing, careful clinical monitoring and continued epidemiologic surveillance remain important. (HEPATOLOGY 2009;49:S28-S34.