OBJECTIVES: Diabetes, hypertension and high cholesterol are all prevalent in the United States. The purpose of this research is to compare medical costs in a managed care setting for individuals with the following diagnoses: diabetes mellitus (DM), hypertension (HYP), and hypercholesterolemia (HC). In so doing, this research will allow payers to understand the comparative resource implications of these common conditions. METHODS: Data from the i3 LabRx Database were used for this study. Adult patients who were diagnosed with DM (N=2,815), HYP (N=6,073), or HC (N=11,442) were included in the study. Differences among the three groups were examined using chi-square statistics for categorical variables and t-statistics for continuous variables. Two- year cost comparisons among the cohorts were conducted using a multivariate regression that controlled for patient characteristics, general health status and comorbid conditions. RESULTS: Compared to the DM cohort, the HYP cohort was significantly older and less likely to be male, while the HC cohort was more likely to be male. Individuals diagnosed with HYP or HC had significantly lower total direct two-year medical costs compared to those in the DM cohort (-$4,588, p<0.0001; and -$9,062, p<0.0001 respectively) as well as significantly lower inpatient costs (-$3,640, p<0.0001; -$13,463, p<0.0001), and outpatient prescription drug costs (-$1,518, p<0.0001; -$2,823, p<0.0001). In addition, patients in the HYP or HC cohorts were found to have significantly lower disease-specific total direct two-year medical costs (-$1017, p<0.0001; -$4941, p<0.0001, respectively) compared to individuals in the DM cohort. CONCLUSION: Results from this study indicated significant differences in demographic characteristics and comorbidities among individuals diagnosed with DM, HYP, or HC. These differences translated into significant cost differences, with patients diagnosed with DM experiencing both higher total medical costs and higher disease-specific medical costs than individuals diagnosed with either HYP or HC.