On April 30, 2015, CMS released a massive new dataset with information on the over one billion prescription drug claims made by 36 million Medicare beneficiaries enrolled in the Part D drug benefit in 2013. CMS stated that the release was part of the Obama Administration’s larger effort to increase transparency in the healthcare system.

The new “Provider Utilization & Payment Data Part D Prescriber Public Use File” includes information on more than 3,400 drugs prescribed by over one million health care providers. For each drug, the data include information such as the number of beneficiaries receiving the drug and the total number of prescriptions; the number of practitioners prescribing the drug; and the “total drug cost.” Individual prescribers are identifiable, but Medicare enrollees are not. CMS also released national-level statistics on the top drugs prescribed by cost and number of claims; the average number and cost of drugs prescribed by practitioner specialty; and generic dispensing rates by geographic area.

In releasing the dataset, CMS noted a number of limitations to its use and stakeholder groups commenting on the release raised similar concerns. For example, the data only include drugs prescribed to Part D enrollees and thus may not reflect providers’ broader prescribing patterns. Additionally, savings from manufacturer rebates to Part D plans are not reflected in the data, and the total drug cost does not represent the actual cost to the Medicare trust funds. Finally, CMS mentioned that there may be errors in the data for various reasons.

This is the first time that CMS has shared unencrypted, provider-level data on drug prescribing. However, CMS has previously released physician-identifiable data regarding utilization, payment, and charges for Medicare Part B services. We have also previously written about other efforts by the Centers for Medicare & Medicaid Services (CMS) to make Medicare data more widely available and these releases appear to be part of that broader initiative.