Days’ Supply Mistakes: A Fast Track to Recoupment

In the best-case scenario, an incorrect days’ supply would be treated as an educational discrepancy with no financial recoupment. This typically happens when the error does not impact the patient’s copay or the pharmacy’s reimbursement, and the auditor simply informs you of the correct days’ supply so that future claims can be submitted accurately.

However, not all payors take this approach. For example, Humana charges a $5 penalty fee for days’ supply errors – even for discrepancies as minor as one day. This fee is often assessed as an administration fee rather than a claim reversal, in an attempt to skirt state audit laws that prevent recoupment on “scrivener’s errors” or “technical discrepancies.”

Full claim recoupment may occur in a billing scenario where the incorrect days’ supply on one claim leads to the medication being refilled early on a subsequent fill. The “refill too soon” rejection will not be appropriately triggered due to the inaccurate days’ supply error on the prior fill. If you bill an inhaler for a 30-day supply (when it should have been a 60-day supply), then refill it a month later, the PBM will recoup that early refill. Additionally, if billing a 60-day supply would have increased the patient’s copay or changed your pharmacy’s reimbursement, the PBM may also look to recoup the difference from the first fill.

What if the insurance only allows a 30-day supply? Unfortunately, it is still up to the pharmacy to ensure refill intervals are appropriate based on the true/calculated days’ supply, not the days’ supply the pharmacy adjudicated due to the plan limit.

Another scenario that may trigger full recoupment involves the potential to bypass a plan limit. This occurs when the PBM rejects the claim stating they will only allow a certain number of doses per day. In an attempt to process the claim, staff may adjust the days’ supply [while keeping the quantity the same] to match the plan’s limit – this drastically increases audit risk! The correct response is to identify and address the underlying rejection message. This may involve contacting the prescriber to get a clarification on quantity per day or initiating a prior authorization process to secure approval for the originally desired dose.

PAAS Tips:

• Do NOT estimate days’ supply. Always calculate the exact days’ supply mathematically from the prescription directions
• Three albuterol inhalers are not a 90-day supply based on typical FDA-approved dosing instructions.
• You should not assume that one tube of cream is always a 30-day supply or that one application is always 1 gram.
• Clarify any ambiguous directions in order to calculate the days’ supply mathematically, add a clinical note to the prescription, and ensure the patient label is updated to reflect the new information.
• Use as directed is not appropriate for insurance. Use as directed per package labeling is appropriate for a few specific medications where the directions are printed on the box like EpiPen® or bowel preps.
• Topical medications should ideally contain grams per application or a maximum grams per day.
• PRN medications for migraine relief should clearly indicate either how long the quantity prescribed is expected to last the patient or how many headaches they are allowed to treat per month.
• Injections that are to be used for “one month” should be billed as a 30-day supply while “every 4 weeks” as a 28-day supply.
• Similarly, injections used on a weekly basis should never be billed as a 30-day supply but in a days’ supply evenly divisible by 7.
• Do NOT bypass a plan limit by billing an incorrect days’ supply. Plan limit rejections are intended to help control costs, provide clinical edits, and assist pharmacies in ensuring patient safety and could lead to a full recoupment if not handled properly.
• If the days’ supply does not come out to a whole number, use appropriate rounding methods to bill the closest whole number.
• For example, 18.2 should be rounded to 18 (with some PBMs also accepting 19), while 18.7 should be rounded to 19 (with some PBMs also accepting 18). Neither should be rounded to 20.
• See the following Newsline articles for more information on specific scenarios:
• From Headache to Hassle Free: Best Practices in Migraine Medication Billing (June 2025)
• Adjusting Quantity or Days’Supply Disproportionately Will Cost You! (December 2024)
• Do The Math and Avoid the Recoupment (August 2024)
• Consider these resources on the Member Portal, under “Proactive Tips”:
• Can You Bill It As 30 Days?
• Exceeding Days’ Supply Plan Limits for Unbreakable Packages
• Be proactive and utilize the PAAS RX Days’ Supply Calculator! Download the app for a free 7-day trial ($5.99/year thereafter) by visiting the Apple App Store or Android Google Play Store, or check out the website at PAASNational.com/app