Medicare prescriber taxonomy requirement effective Sept. 11 

Effective Sept. 11, 2018, in response to new state laws, our pharmacy benefit manager, Express Scripts, Inc. (ESI) is launching new rules to follow prescriptive authority logic. To be compliant, providers need to pre-select their correct taxonomy code on the National Plan and Provider Enumeration System (NPPES) website.


The Centers for Medicare & Medicaid Services (CMS) recently released guidance to the industry that indicates that taxonomy will have a critical role in defining how Medicare claims process. The taxonomy or taxonomies associated to a prescriber's National Provider Identifier (NPI) will tell claims systems all over the country whether a claim should process or reject. To ensure continued member access and data accuracy, it is crucial that you be familiar with what taxonomy is, how it works and that your NPI is associated with a valid taxonomy code that correctly reflects what you do.

This new requirement and logic validates that mid-level practitioners are appropriately following the new prescribing laws for Michigan based on the taxonomy code they've chosen on the NPPES website.

Provider impact

Recent reports show the highest volume of non-compliant providers are psychologists, some of which who are out of state. No contracted ACNs, POs, or PHOs are on the non-compliant list.

What if a provider has multiple taxonomy codes?

With this implementation, we are aware that prescribers can have multiple taxonomies that may cross different license types. For example a doctor may have both a physician assistant taxonomy as well as a medical doctor taxonomy. In those cases, we would process on what was least restrictive.

What does the future of this initiative look like?

This new state prescriptive authority logic will be rolled out in multiple phases. This first phase is the most straightforward as it will include all rules for mid-level practitioners who do not have authority to prescribe any prescriptions in a specified state. The subsequent phases will contain rules for both non-controlled and controlled substances that have more granular restrictions.