Washington Prescription Drug Program (WPDP)

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Quarterly Washington Preferred Drug Lists (PDL)

On the Washington PDL each program's status is listed separately. Preferred or not covered is noted, if a status is left blank the drug is nonpreferred. As an Endorsing Practitioner, the Washington PDL tells you what drugs can be therapeutically interchanged for a preferred drug.

2024 Washington PDL

Quarter one | Quarter two | Quarter three | Quarter four

If you are looking for the preferred status of a drug that is not included in the Washington PDL, please check the specific program website.

Drug class updates

Changes to preferred drugs covered under the Washington Preferred Drug List and their effective dates are listed below.

Drug status on the PDL

Defining a drug’s “preferred” or “nonpreferred” status on the PDL:

  • A “preferred” drug on the PDL is not subject to the Therapeutic Interchange Program (TIP).
  • A “nonpreferred” drug on the PDL is subject to TIP when it is included in a Drug Effectiveness Review Project (DERP) report. If the prescription is written by an endorsing practitioner, a pharmacist will substitute the "nonpreferred" drug for a preferred drug in that class.
  • If a drug is part of a PDL drug class, but it has not been reviewed by DERP, it is considered "nonpreferred". It is not subject to TIP or dispense as written (DAW), and will be covered according to each program's benefit design.

Selection process of preferred drugs on the PDL.

Archived drug classes

  • If a drug classes is noted as archived under comments, the drug class will remain on the PDL and the committee's last motion will remain in effect until changed by the committee. The agencies may conduct updated cost analyses of these drug classes without additional committee approval so long as any resulting changes in the preferred status of a drug remains consistent with the committee's last motion for that drug class.
  • The committee may review the archive status of a drug class upon its own initiative, or by request of the participating agencies at any time.