The Medicare Part D Opioid Prescribing Mapping Tool, updated in November 2017, is an interactive tool that shows geographic comparisons, at the state, county, and ZIP code levels, of de-identified Medicare Part D opioid prescription claims – prescriptions written and then submitted to be filled – within the United States. The mapping tool presents Medicare Part D opioid prescribing rates for 2015 as well as the change in opioid prescribing rates from 2013 to 2015. New for this release is additional information on extended-release opioid prescribing rates as well as spatial analyses to identify “hot spots” or clusters.