The Therapeutic Interchange Program (TIP) has developed a process allowing physicians and other prescribers to endorse the Washington State Preferred Drug List (PDL), and requires pharmacists to automatically substitute the preferred drug for non preferred drugs prescribed by these practitioners unless the prescription is for a refill of an antipsychotic, antidepressant, chemotherapy, antiretroviral, or immunosuppressive drug, in which case the pharmacist shall dispense the prescribed non preferred drug.

You can register as an Endorsing Practitioner online now! Look up an Endorsing Practitioner now! Access Account

How Does a Practitioner Become an Endorsing Practitioner?

There are two ways:

How Long Will it Take For my Endorsement Status to Update?

It will take about five business days from the receipt of the completed, signed form.

How Do I Look Up a Washington Practitioner's Endorsement Status?

There are two ways:

Why Become an Endorsing Practitioner?

In Washington State, when a licensed practitioner endorses the PDL and prescribes a drug for a patient covered by Medicaid (HCA), the Department of Labor & Industries (L&I), the Uniform Medical Plan PPO (PPO), pharmacies will automatically interchange a preferred drug for any non preferred drug in that therapeutic class. An endorsing practitioner can also indicate "dispense as written" (DAW) on a prescription and no substitution will be made. This saves time for your staff seeking prior authorization for non preferred drugs.

What is Therapeutic Interchange?

Therapeutic interchange occurs when any endorsing practitioner writes a prescription and the pharmacist automatically interchanges a preferred drug for any non preferred drug in that therapeutic class. After making the interchange, the pharmacist will notify the practitioner of the drug and dosage dispensed to the patient. An endorsing practitioner can indicate "dispense as written" on a prescription and no substitution will be made.

Here's how each program works if a non-endorsing practitioner prescribes a non preferred drug in one of the PDL classes and indicates "dispense as written" (DAW):

  • Uniform Medical Plan (PPO): The pharmacist cannot make a substitution, even for a generic equivalent. The patient would receive the non preferred drug as prescribed, at a higher cost.
  • L&I: A non-endorsing practitioner does not qualify for the "dispense as written" exemption and the non preferred drug would not be payable unless the pharmacist or practitioner calls with medical justification.
  • Medicaid: The provider is required to contact the Medicaid Pharmacy Authorization Line or fill out the form to request an authorization for a Non-preferred Drug.