Improve Medication Adherance with 90-Day Supplies

Reflection: Do you consider a 90-day supply when approving medication refills?

  • Writing for a 90-day supply for chronic diseases improves patient medication adherence.

Says who: The real-world, recent (2016) data. Payer data of Georgia members noted increases in adherence for prescriptions written for 90 days, compared to those written for less (30 days, 60 days).

  • For antidiabetic medications, medication adherence increased to 81% from 76% (a 5% increase).
  • For ACE/ARBs, medication adherence increased to 82% from 74% (an 8% increase).
  • For statins, medication adherence increased to 79% from 73% (a 6% increase).

Why does this work? 90-day supplies translate to fewer refill requests and pharmacy visits for patients.


  1. Consider prescribing for a 90-day supply when prescribing chronic medications for diabetes (such as metformin or even insulin), hypertension (such as ACE/ARBs- lisinopril/ losartan), and hyperlipidemia (such as statins- atorvastatin).
  2. Check your electronic health record (EHR) settings. Can you set a default for a 90-day supply?

Writing a 90-day supply will not present insurance barriers for patients. Pharmacies can dispense 30-day supplies on a 90-day prescription to meet insurance coverage specifications. Medicare and Medicaid mostly cover 90-day supplies for chronic medications.

Extra readings:

Batal HA, Krantz MJ, Dale RA, Mehler PS, Steiner JF. Impact of prescription size on statin adherence and cholesterol levels. BMC Health Serv Res. 2007 Oct 25;7:175. PubMed PMID: 17961256; PubMed Central PMCID: PMC2174936.

Adapted from:


Questions or comments? Reach out to the Piedmont Clinic Population Health Clinical Pharmacist, Michell Butler, PharmD (

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