On June 29, 2012, the Rappahannock Area Health District in northwestern Virginia received a report of an acute hepatitis B virus (HBV) infection in an elderly resident of an assisted-living facility (ALF). The resident reported no risk factors for HBV infection except assisted monitoring of blood glucose (AMBG), which has been implicated in the transmission of HBV in ALFs and other long-term-care facilities. Rappahannock Area Health District investigated the source of the infection and the scope of transmission. Investigators observed facility infection control practices and procedures and conducted staff interviews. The facility was scheduled to close July 31, 2012, necessitating prompt response before residents were transferred.