ProPublica Prescriber Checkup Data Sources July 3, 20140 ProPublica Prescriber Checkup provides prescribing data from Medicare's prescription drug benefit, known as Part D. The data for 2011 includes nearly 1.2 billion prescriptions by 1.6 million doctors, nurses, and other providers. The database lists about 364,000 of those providers who wrote 50 or more prescriptions for at