CareOregon, an Oregon-based not-for-profit Medicaid health plan, successfully piloted a “CareSupport” model that identifies high-risk members and clinically stratifies them for intervention. Internal analyses indicate that CareSupport lowers utilization and cost; CareOregon, however, has lacked patient-reported outcome data on the health-related quality of life (HRQL) of CareSupport participants. Between September 2005 and November 2006, we conducted a pilot study in which the Health Utilities Index Mark 3 (HUI3), a generic preference-based measure of health status and HRQL, was integrated into CareOregon’s existing screening algorithm for possible admission into CareSupport. We obtained baseline data on 616 CareSupport candidates and 4-month HUI3 follow-up data on 143 candidates (104 CareSupport, 39 non-CareSupport). On a 0.00 (dead)-to-1.00 (perfect health) scale, the mean overall baseline HUI3 score for CareSupport patients was 0.18 (0.20 for non-CareSupport patients), comparable to baseline means reported elsewhere for much older patients immediately after suffering serious acute medical events, such as stroke or hip fracture. A 0.05 mean 4-month improvement in overall HRQL among CareSupport enrollees relative to non-CareSupport enrollees was clinically important but not statistically significant. A 0.10 improvement in HUI3 emotion was both statistically significant and clinically important. Study results provide good preliminary evidence of the value of patient-reported outcomes in clarifying individual illness burden and assessing intervention effectiveness.