The Hospital-Acquired Condition (HAC) Reduction Program (HACRP) assesses penalties on hospitals with high rates of HAC. This study explores the impact of repeated HACRP penalties on hospital improvement and variation by hospital characteristics. When considering all hospitals, repeated HACRP penalties resulted in improved HAC scores. Hospitals with disproportionate shares of Medicare and Medicaid patients showed less improvement; the researchers note that the differential improvement may be due to resource limitations at hospitals serving vulnerable populations (i.e., Medicare and Medicaid patients).