What do all the abbreviations mean on my formulary?

Understanding your Formulary · updated May 31, 2023

Some abbreviations on your Medicare Part D plan's formulary are for Usage Management Restrictions or to further clarify the coverage details under your particular Medicare Part D prescription drug plan. The abbreviations that you might find on your formulary may include:

PA = Prior Authorization,
PA-NS = Prior Authorization New Starts,
PA-BvsD = Prior Authorization-BvsD Only (Part D vs. Part B Prior Authorization Only),
QL = Quantity Limits,
ST = Step Therapy,
ST-NS = Step Therapy New Starts,
LA = Limited Access,
MS = Mail Service Available

For more about Medicare Part D prescription drug plan abbreviations and acronyms, please see our Frequently Asked Question: "What are the meanings of the acronyms and abbreviations associated with the Medicare Part D program?" located at
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