OBJECTIVES: To compare healthcare use, healthcare costs, and work loss costs in employees with fibromyalgia (FM) to matched samples of employees with osteoarthritis (OA) and non-FM controls. METHODS: Samples were selected from a U.S. claims database of privately insured beneficiaries. Employees in the FM sample had „dƒn2 fibromyalgia diagnoses in 1999-2005 (with „dƒn1 in 2002-2005) and were continuously enrolled in 2005. Controls and employees with OA had no FM claims and were matched to the study sample on age, gender, and region. Costs are reported for 2005 experience. Nonparametric Wilcoxon tests were used to determine statistically significant differences in skewed variables including costs. Chi-square tests were used to test for differences in for categorical variables. RESULTS: Mean age in the FM sample was 50.1 years and 51.6% were female. Compared to control and OA samples, employees with FM had higher rates of depression, anxiety, chronic fatigue syndrome, and many pain diagnoses. The FM sample used more medical care overall, especially emergency department visits, specialty physician visits, and prescriptions. Direct (medical and prescription drug) costs in the FM sample were significantly higher than control sample costs ($7,286 vs. $3,915, p<0.0001), and approached OA sample costs ($7,286 vs. $8,325, p=0.3758). Prescription costs comprised a relatively large proportion of total FM costs; prescription cost levels were comparable to employees with OA ($1,630 vs. $1,341, p<0.3541) and significantly higher than controls ($1,630 vs. $755, p<0.0001). Work loss costs in the FM sample ($2,913) were significantly higher than those of control ($1,359, p<0.0001) and OA ($2,537, p<0.0001) samples. CONCLUSION: Fibromyalgia imposes significant economic burden. Average total costs among employees with fibromyalgia were almost twice those of matched controls and approximated costs of employees with osteoarthritis. Indirect costs were more than double those of controls and even exceeded costs of osteoarthritis patients with similar demographic profiles.