An important question for facilities monitoring acute care bed admissions with proprietary criteria is whether these methodologies remain valid after substantial changes to the criteria sets. This is especially true for publicly funded hospitals whose medical and social mission is often broader than that of private sector facilities for which insurance-based claim review is most relevant. To further address this issue, we used sequential sets (1994 and 1995) of InterQual Intensity, Severity, and Discharge criteria to assess a cohort of patients referred to our Veterans Affairs facility as acute care admissions between December 1, 1994, and February 28, 1995. We found that the appropriateness rate for the subset of medical admissions dropped from 88% when using the 1994 criteria set to 49% when using the more stringent 1995 criteria set (P < 0.001). We conclude that substantive changes to previously validated criteria sets require revalidation. Furthermore, consideration should be given to the role that insurance-based utilization review should play in publicly funded hospital systems.