OBJECTIVES:   To quantify the relationship between employees’ self-reported health status obtained from annual health risk assessments (HRAs) and subsequent year medical expenditures. METHODS:   Data were obtained from the MarketScan Research Databases, which includes health care information pooled from large US employers.  Employees were identified who completed HRAs in 2006 and had full-year data on medical expenditures in 2007.  Four general health status measures, each with 5-point Likert scales, were considered:  overall health the past 6 months (1=excellent, 5=poor); health impact on work and daily activities (1=rarely sick, 5=significant interference); general mood (1=very happy, 5=unhappy and have considered getting help); stress (1=seldom stressed and coping well, 5=often stressed and trouble coping).  Medical expenditures for each individual included total 2007 payments to health care providers for inpatient, outpatient, and pharmacy services covered by the employer health plan.  General linear models were used to estimate the association between health status and future expenditure. RESULTS:   A total of 72,940 employees responded to at least one health status question in 2006 and had full-year claims data for 2007.  Mean age was 42 years and 56% were male.  The four health status measures were highly intercorrelated ( Range of Pearson r: 0.15-0.52).  Each measure was strongly associated with future medical expenditures (p<0.0001).  The rate of increase in expenditures per one point increment was 30.2% for overall health, 49.5% for health impact, 16.4% for mood, and 12.5% for stress.  Inpatient and pharmacy expenditures were generally more responsive to worsening health status than outpatient. CONCLUSIONS:   Self-reported health status of employees is strongly associated with future medical expenditure.  Data from employer-sponsored HRAs may therefore provide a useful indicator of population health and of the benefits of wellness interventions.