Opioids prescribed to Medicare Part D enrollees by NPs/PAs. The MME prescribed by primary care NPs/PAs is displayed as a percentage of the total MME prescribed by all primary care providers (MDs, NPs, PAs) and ordered by quintile (shown in color). The number corresponding to each state shows the mean MME per Part D enrollee which primary care NPs/PAs in that state prescribed. MD, medical doctor; NP, nurse practitioner; PA, physician assistant; MME, morphine milligram equivalents.