Inventory Purchase Reminders for Successful Audits

With a 29% increase in PBM audits in 2023, PAAS National® wants to help you avoid PBM scrutiny, especially when it comes to drug procurement.

PBMs conduct invoice audits to confirm pharmacies have purchased enough medication to support the claims they have billed for. This is the primary method PBMs can identify false/phantom claims, where a pharmacy is billing for medications that never get dispensed. The auditor will reconcile claims billed with invoices provided, over a certain timeframe. After the reconciliation is complete, any inventory shortages must be explained or resolved by the pharmacy, or it could result in recoupment of claims and even termination of contract if there are substantial issues.

PAAS analysts have assisted with countless invoice audits and are eager to provide helpful tips for success.

PAAS Tips:

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  • Take the proper steps to vet any wholesaler you intend to purchase from
    • Confirm they are licensed in your state
    • Check the NABP website for Accredited Drug Distributors (formerly “VAWD”)
    • Verify you have a direct contact to request invoices on a timely manner
    • Be sure wholesaler can provide Drug Supply Chain Security Act (DSCSA) information if requested
  • Diabetic test strips have unique requirements
    • OptumRx requires OTCs dispensed via prescription to be bought from a licensed wholesaler accredited by NABP
    • Caremark and Express Scripts require Authorized Distributors of the manufacturer
      • If the pricing is substantially better, they’re likely not authorized – even if they’re affiliated with one that is (i.e. McKesson-authorized; River City Pharma & Masters-not authorized)
    • Authorized Distributors can be verified at the links below
      • Abbott
      • Ascensia (click on “distributors” at the bottom of the page)
      • LifeScan
      • Roche
      • Trividia Health
    • Limit pharmacy to pharmacy purchases to a minimum
    • Be sure the NDC billed is the NDC dispensed, this includes package size
      • Bar code scanning is highly recommended during the filling process
    • Remember Caremark requires pharmacies to notify them of any bulk purchases
    • Verify your pharmacy is appropriately reversing claims that are not dispensed

Need assistance with an invoice audit? Engage PAAS early for information and guidance for the best possible outcome. Call (608) 873-1342 or email to

Dana Westberg, CPhT