Current recommendations have not resulted in routine vaccination of correctional facility inmates for hepatitis B. We investigated two hepatitis B outbreaks. Outbreak 1 involved 4 cases epidemiologically linked to persons who had been in jail. Outbreak 2 involved 48 community cases; 69% had a history of incarceration. Two-thirds of the cases in these outbreaks might have been prevented by a program of routine vaccination of local jail inmates. Priority should be given to developing and supporting practical programs to vaccinate the high-risk populations in correctional facilities against hepatitis B.