Do The Math and Avoid the Recoupment

Proper mathematical calculations are critical to billing prescriptions correctly. The action of translating directions on the prescription into a mathematical equation seems simple, but PAAS National® analysts see claims billed with incorrect days’ supply every day! Though many PBMs may not recoup for a simple days’ supply calculation error, the error itself can cause additional discrepancies on the claim, which usually do result in a financial penalty. For instance, if the pharmacy bills three 10.2 g Symbicort® 160 mcg/4.5 mcg inhalers with directions of 1 puff BID as a 90 days’ supply when it should be a 180 days’ supply, that will likely result in several discrepancies. First, an invalid days’ supply discrepancy. Second, the claim is usually flagged with an overbilled quantity discrepancy which results in a partial recoupment when the plan limit is 30 or 90 days. Third, it could cause a refill too soon penalty on the next fill which would result in a full recoupment of the subsequent claim. The penalties and subsequent recoupments can add up fast! 

For many medications, the mathematical calculation is straightforward; however, not all medications are easily calculated. Below is a table of the common days’ supply calculation pitfalls and ways to avoid them.

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Medication FormulationCommon Days’ Supply Calculation MistakesBest Practice to Avoid Days’ Supply Calculation Errors
Colonoscopy Prep KitsNon-calculable directions such as:“Use as directed”“Follow instructions provided by gastroenterology” Directions on the prescription and patient label should indicate whether a single-day regimen or a split-dose regimen is being followed so a proper days’ supply can be billed (1 or 2 days, respectively)Clarify “use as directed” instructions by contacting the prescriber’s office to update the directions to “use as directed per package labeling”, annotate the clarification with a clinical note, update the directions on the patient label, and (if audited) be sure to include a copy of the instructions found within the manufacturer’s product labeling
Eye DropsNon-calculable directions such as “Use in affected eye(s)”Forgetting to consider product beyond use dating (BUD)Ensure the prescription and patient label indicate which eye or eyes are being treatedEnsure a frequency is listed on the prescription and labelIf the patient is doing a short course, then discarding the remainder of the bottle, be sure the hardcopy and the patient label reflect the treatment duration and that they will throw away the remainder; the correct days’ supply would be the same as the treatment duration.If the patient is doing a short course but there are no directions to discard the remainder, calculate the days’ supply based on the drops/mL specified by the PBM to which the claim is being billed; refer to the PAAS Eye Drops chart for additional guidanceConsider the BUD of the eye drops, where applicableRefer to manufacturer guidance on drops/mL for unique products such as Miebo®, Veyve®, and Vyzulta®
InsulinSliding scale insulin without a max daily dose (MDD)Insulin titration to meet a specific blood glucose goal without a MDDForgetting to consider product BUDObtain a MDD for sliding scale insulin or insulin titrations to meet a blood glucose goal; document the MDD on the prescription and on the patient labelDocument priming units if used in days’ supply calculations for insulin pensConsider BUD on pens and vials 
Migraine Rescue MedicationsNon-calculable directions such as:“Use as needed”“Use as directed”No indication of whether an additional dose can be taken (after the applicable waiting period) for the same episode for qualifying medications and dosesIgnoring dosage and administration guidance from the package insert or adjudication messaging Ensure the prescription includes the amount of medication to be taken per administration and a specified frequency of administration (including the frequency of repeat dosing)Obtain the allowable number of migraines the patient can treat per week or per month, document this information on the prescription and on the patient’s label and use this information in the days’ supply calculationPay attention to dosing and administration guidance within the package insert and to the payer’s messaging upon claim adjudication to avoid audit triggers for excessive amounts billed 
Pancreatic EnzymesMissing the total number of capsules per dayMissing the number of snacks per dayThe directions on the prescription and the patient label should include either:The total number of capsules per day the patient can consumeThe number of meals and snacks per day with which the medication is takenAuditors will generally assume 3 meals/day but the number of snacks per day should be indicated on the prescription and labelRemember to account for the FDA product label update from 10/12/2023 which now requires all strengths of Creon® to be dispensed in the manufacturer’s bottle
Topicals (creams, gels, ointments, solutions) Non-calculable directions such as:“Use as directed”“Apply to affected area once daily”Santyl® ointment missing the wound length and width, missing the treatment duration, not using the Santyl® calculator, forgetting to account for inherent rounding issues with manufacturer’s online calculatorJublia® directions to “apply to toenails once daily” Ensure the hardcopy and the patient label list the grams/application or grams/day the patient is usingReview the PAAS Topical Creams and Ointments tool for guidance on the Fingertip Unit (FTU) method1 FTU = 0.5 gThe prescription must have the site(s) to which the topical is being applied and an application frequencyDocument your FTU calculation on the prescription or within the electronic prescription recordSantyl® ointment prescriptions require the wound(s) length and width (in cm) plus the treatment duration and use of the manufacturer’s online calculator or the PAAS Rx Days’ Supply Calculator AppJublia® prescriptions (and the patient label) must include the number of applications needed per day. Each toenail being treated would require one application, except each big toenail treated would require two applications. A 4 mL bottle contains approximately 200 applications.
Vaginal CreamsNon-calculable directions such as:“Use as directed”“Pea-sized amount”“One application twice weekly”Estrace® (estradiol) 0.01% vaginal cream comes in a
42.5 g tube and has a graduated applicator with measurements from 1 g to 4 g, in 1 g incrementsPremarin® (conjugated estrogens) vaginal cream comes in a 30 g tube and has a graduated applicator with measurements from 0.5 g to 2 g, in 0.5 g incrementsA “pea-sized amount” should be clarified to be an amount in grams (e.g., insert a pea-sized amount (0.25 g) vaginally twice per week)An “application” is not specific enough to calculate a days’ supply; however, “1 applicatorful” or “half an applicatorful” would be sufficient along with a frequency (e.g., insert half an applicatorful twice weekly for Estrace® would be 2 g twice per week and for Premarin® would be 1 g twice per week)

PAAS Tips:

  • A complete clinical note should include four elements:
    1. The date/time of the call
    2. The name and title of the person you spoke with at the prescriber’s office
    3. The clarification
    4. Your initials
  • Ensure the instructions on the patient label are updated to reflect any clarification made to the directions on the prescription so the patient receives the full set of instructions at the time of dispensing
  • Follow the Can You Bill It As 30 Days? (The ILQ Process) guidance when a claim billed with the correct days’ supply rejects due to plan limitations exceeded
Sara Hathaway, PharmD
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