2024 Self-Audit Series #9: Eye Drop Days’ Supply

Billing the accurate days’ supply for eye drops can be challenging. Despite what is drilled into pharmacists during schooling, there is no industry standard for drops/mL, and PBMs often use their own specific conversion factors. This variability adds complexity to accurately determining the appropriate days’ supply.” The PAAS National® Eye Drop Guidance chart has been created for our members to have the most up to date information from the major PBM provider manuals to assist them with this process. 

Pharmacies must also take into consideration several eye drops that do not fall under the typical drops/mL conversion due to beyond use dating, single use vials, or atypical drop size. Recognizing these extra billing considerations is imperative to avoid potential audit issues.

Please refer to the following Newsline articles for information on some of these specific eye drops:

PAAS Tips:

Become an audit assistance member today to continue reading this article. As a member, you’ll have access to hundreds of articles and receive our monthly proactive newsletter!

  • Verify the prescription has mathematical instructions for use and clarify any ambiguous directions
  • Download the PAAS National® Rx Days’ Supply Calculator app
  • Do not assume the days’ supply indicated on electronic prescriptions is correct, always calculate days’ supply according to instructions for use
  • Best practice is for quantity prescribed to include a unit of measure; however, if written for a quantity of “1 bottle”, it should be interpreted as the smallest package size
  • When billing a PBM not listed on the Eye Drop Guidance, PAAS recommends using 15 drops/mL for suspensions or emulsions, and 20 drops/mL for solutions, unless otherwise specified by the manufacturer
  • Billing eye drops for LTC patients carries the same audit risk, refer to the following June 2022 Newsline article, Beyond-Use Date vs. Nursing Home Storage Policy – Avoid this Recoupment Trap
  • Prescriptions with a treatment duration (e.g., “use for 10 days”) that is less than calculated days’ supply, should still be submitted per calculation

PAAS Audit Assistance members can search the Newsline archive for keyword “2024 self-audit” to read previous articles in this series. If you have any questions on accessing the Member Portal, or need help adding employees so they have access, please contact us.

Dana Westberg, CPhT