With the increasing frequency of antibiotic-resistant gram-positive infections in the United States, many patients are being treated outside the hospital setting. The majority of studies on the cost of outpatient antimicrobial therapy involve retrospective medical record review or prospective data collection. These methods tend to be expensive and time consuming, and often fail to produce a sufficiently large sample size. Analysis of insurance claims data offers a convenient approach for studying the costs associated with outpatient therapy for gram-positive infections. To demonstrate this approach, a study of the cost of intravenous vancomycin home care therapy was conducted using claims data from a large insurance company.