OBJECTIVES: Estimate annual per-patient medical, drug, and work-loss costs of diabetic foot ulcer (DFU) using de-identified administrative claims data. METHODS: DFU patients and non-DFU diabetic patients (controls) were identified using two databases: ages 65+ from a 5% random sample of Medicare beneficiaries (Standard Analytical Files, 2007-2010; DFU N=29,681, controls N= 201,757) and ages 18-64 from a privately-insured population (OptumInsight, 2007-2011; DFU N=5,681, controls N= 113,337). Patients were required to be continuously eligible during the 12 months before (baseline) and 12 months after (study period) the index date (ie, the date of the most recent DFU diagnosis following 12 months without DFU diagnoses (DFU group); or the date of a random medical claim (controls)). DFU patients were matched to controls using propensity scores to account for baseline differences in demographics, comorbidities, resource utilization, and costs. Medical costs during the study period were calculated for both Medicare and privately-insured patients. Because drug and work-loss (absenteeism or disability) data were not available for Medicare patients, these costs were estimated for the privately-insured sample only. Wilcoxon signed-rank tests were used to compare differences in study period costs. RESULTS: Data for 4,536 matched pairs of privately-insured and 27,878 matched pairs of Medicare patients were analyzed. Incremental medical costs for DFU patients were $11,296 for Medicare ($27,040 vs $15,743) and $15,329 for privately-insured ($25,931 vs $10,602) patients. Two-thirds (66%) of the cost differential among the privately-insured was attributable to excess inpatient costs. For Medicare, all places of services (eg, inpatient, outpatient/physician, emergency department) contributed approximately equally to the medical cost differential. Among the privately-insured, DFU patients had excess drug costs of $958 ($4,377 vs $3,420) and excess work-loss costs of $3,053 (absenteeism: +$1,490, disability: +$1,564). (Comparisons significant at p<0.0001.) CONCLUSIONS: These findings suggest that presence of DFU imposes substantial burden on payers beyond that of standard diabetes care.