Overall annual influenza vaccination rate has slowly increased among health care workers but still remains below the national goal of 90%. To compare hospitals that mandate annual health care worker (HCW) influenza vaccination with and without consequences for noncompliance, a 34-item survey was mailed to an infection control professional in 964 hospitals across the United States in 4 waves. Respondents were grouped by presence of a hospital policy that required annual influenza vaccination of HCWs with and without consequences for noncompliance. Combined with hospital characteristics from the American Hospital Association, data were analyzed using χ(2) or Fisher exact tests for categorical variables and t tests for continuous variables. One hundred fifty hospitals required influenza vaccination, 84 with consequences (wear a mask, termination, education, restriction from patient care duties, unpaid leave) and 66 without consequences for noncompliance. Hospitals whose mandates have consequences for noncompliance included a broader range of personnel, were less likely to allow personal belief exemptions, or to require formal declination. The change in vaccination rates in hospitals with mandates with consequences (19.5%) was nearly double that of the hospitals with mandates without consequences (11%; P=.002). Presence of a state law regulating HCW influenza vaccination was associated with an increase in rates for mandates with consequences nearly 3 times the increase for mandates without consequences. Hospital mandates for HCW influenza vaccination with consequences for noncompliance are associated with larger increases in HCW influenza vaccination rates than mandates without such consequences.