PBM Audits in Community Pharmacy: The High-Risk Categories

If your pharmacy has been audited recently, there's a good chance diabetic testing supplies were on the list. Blood glucose test strips, lancets, and meters consistently rank as the most audited category in community pharmacy. Diabetic supplies are dispensed constantly, often as 90-day fills, often auto-refilled, and often for patients juggling multiple prescribers. The volume alone makes the category statistically likely to entry errors. Moreover, large volume gives auditors a large sample to utilize in an audit. If a pharmacy files a claim for an NDC number that doesn’t have a corresponding purchase history, the pharmacy is instantly under both PMB and licensure scrutiny.

PBMs are also concentrating audit activity on specialty medications, GLP-1 products, high-reimbursement drugs, controlled substances, and compounded products. Here's why each category draws scrutiny, and how a pharmacy can get ahead of an audit instead of just reacting to one.

Common audit findings and what you can do

Days' supply math is easy to get wrong — and easy to audit. Test strip quantity is supposed to track how often a patient actually tests, per the prescriber's directions. A patient testing three times a day needs roughly 90 strips a month, not a 100-count box dispensed as a "30-day supply" when it actually covers more. Auditors compare the quantity billed against the directions on file, and mismatches are one of the most common findings in this category.

What you can do: Match quantity to documented frequency of use. Before dispensing, confirm the prescriber's testing frequency and calculate days' supply accordingly. Build this check into your workflow rather than relying on the default quantity in the system. Flag any prescription where the billed days' supply doesn't match the directions.

Wholesaler sourcing requirements. Several major PBMs now require pharmacies to purchase diabetic test supplies exclusively from wholesalers or distributors authorized by the original device manufacturer. If a pharmacy buys from a secondary or gray-market source, even a legitimate, authentic product, the claim can be flagged as an “invoice shortage”: the dispensed quantity isn't supported by qualifying purchase documentation. This has become the single biggest source of diabetic supply recoupments industry-wide, and it can also trigger network termination.

What you can do: Buy exclusively from PBM-authorized distributors. Check each PBM's published authorized distributor list before sourcing diabetic test supplies. Keep that list current as distributors change. Retain invoices that clearly tie purchased quantities to dispensed quantities, by NDC, for as long as your PBM contracts and state law require.

Brand/generic and NDC switching. Test strips are often substituted between brands or repackaged under different NDCs. If the NDC billed doesn't match what was physically dispensed, or if codes don't reflect what the prescriber actually authorized, that's a clean audit finding requiring no judgment call from the auditor.

Pharmacies must have a clean transaction history to demonstrate supplies were purchased from an authorized distributor.

What you can do: Verify NDC accuracy on every fill. The NDC billed should be the NDC physically dispensed, every time. Double-check billing entry against what the prescriber actually specified, and what was actually dispensed, particularly when a generic substitution or different package size is used.

Refill-too-soon patterns. Diabetic supplies are refilled often, which makes "refill too soon" claims more likely to occur and easier to spot in a claims report. Without a documented explanation of an early refill (lost supplies, dose change, stockpiling before a trip), these claims are routinely recouped.

What you can do: Document every refill-too-soon. If a strip or lancet refill happens earlier than expected, note the reason in the patient record at the time of dispensing, not after an audit letter arrives. Lost product, a dosage or testing-frequency change, an upcoming supply gap, or patient adherence are all legitimate reasons but only if they're documented contemporaneously.

Signature and delivery documentation gaps. Many diabetic supplies are shipped or delivered rather than picked up at the counter, which means proof-of-delivery and signature logs are frequently incomplete. Missing this documentation is one of the easiest findings for an auditor to make.

What you can do: Tighten delivery and signature capture. For any diabetic supply delivered or mailed, keep proof of delivery and, where required, a signature log. If your pharmacy uses a courier or shipping service, make sure those records are retrievable and tied to the specific claim.

GLP-1 medications. GLP-1s sit at the intersection of high cost, high demand, and heavy utilization management. Most fall under a specialty formulary restriction. A large majority carry additional steps which must occur prior to dispensing. The volume of prior authorization requests, plus frequent dose changes and product switches (different pens, different strengths), creates a lot of opportunity for billing mismatches. Simply filling a large legitimately prescribed GLP-1s places a pharmacy under the microscope. Compounded GLP-1 products add another layer of risk: they aren't FDA-approved, several PBMs and pharmacy groups have flagged quality and dosing concerns, and claims involving compounded semaglutide or tirzepatide draw extra scrutiny.

What you can do: Ensure that each GLP-1 is dispensed with a full drug utilization review. Ensure there is a legitimate medical purpose to the dispensation as required in state-level dispensing laws. If your pharmacy fills a large volume of GLP-1s from a single provider, be prepared to explain the nature of the relationship with the prescriber. Auditors look for reasons a pharmacy may be engaged in fraud, waste, or abuse. Proper documentation is the tool that overcomes allegations of wrongdoing.

High-reimbursement drugs generally. Any drug with a high per-claim reimbursement, brand-name or specialty, becomes a more attractive audit target simply because the dollar exposure per error is larger. Auditors look closely at NDC accuracy, days' supply, and whether the quantity dispensed lines up with what a patient would plausibly use.

What you can do: Ensure the NDC number that is claimed matches the NDC that was purchased and matches the NDC number that was dispensed. Failing to reverse a claim from a return-to-stock item creates an audit problem – there is a claim for a NDC number without a corresponding purchase. Fraud instantly becomes the allegation.

Controlled substances. Controlled substance claims carry the added layer of DEA compliance on top of PBM billing rules. Audits here often focus on early refills, accurate inventory, quantity and refill limits, prescriber DEA number accuracy, and red flags associated with diversion (pattern prescribing, cash-plus-insurance combinations, out-of-area patients). Pharmacists carry a corresponding responsibility when dispensing controlled substances. Findings can trigger board of pharmacy referrals in addition to PBM recoupment.

What you can do: Perform controlled substance audits on a weekly or monthly basis. Ensure that all controlled substance records are kept exactly as required by the DEA. Maintain documentation that demonstrates how red flags were cleared or not cleared.

Compounded medications. Compounds are audited heavily because they don't have a standard NDC tied to a single manufactured product, which makes ingredient sourcing, formula documentation, and component invoicing central to whether a claim holds up. Missing ingredient invoices or formulas that don't match the billed claim are common findings, and this category often overlaps with GLP-1 audit activity.

What you can do: Any compounded prescription drug product must be tied to a statement of necessity from the prescriber which shows why the patient benefits from a compounded drug product. Compounding practices must meet minimal competency standards.

Specialty medications. Specialty drugs are expensive, often require prior authorization, and frequently involve limited-distribution networks or third-party coordination. All of these factors create an environment where documentation can fall out of sync with the claim. PBMs reason that because the pharmacy received payment and dispensed the drug, it bears responsibility for proving the record supports the claim, even when a prior authorization was handled by an outside vendor or the prescriber's office.

What you can do: Ensure there are no gaps in prior authorization documentation, no mismatched diagnosis codes, and there is proof of patient receipt.

How to be proactive, not just reactive

Most recoupments aren't caught at the counter; they're caught later, when a PBM pulls a claims sample. The pharmacies that fare best treat audit-readiness as a daily habit rather than something to scramble for after a notice arrives.

Run regular self-audits. Periodically pull a sample claims and check them the way a PBM auditor would: invoice support, medical necessity, days' supply math, NDC accuracy, and delivery documentation. Catching a pattern internally is far cheaper than catching it during a PBM audit.

Look for patient demographic factors such as a large volume of expensive drugs written by a single provider or patients traveling over distance to fill prescriptions. While these examples may be completely justified at a pharmacy practice site, the justification must be documented to withstand audit scrutiny

Train staff specifically on this category. Because diabetic supplies involve sourcing rules that don't apply to most other products, make sure all pharmacy employees know the authorized distributor requirement explicitly. A well-intentioned purchase from an unauthorized but legitimate wholesaler can still trigger a full recoupment.

Having singular staff members focus on dedicated tasks in the billing process removes the risks created by fractured, unclear roles. When multiple people are doing parts of the same job, the tendency to create a data entry error increase significantly.

Respond to audit requests promptly and completely. If an audit notice arrives, gather the prescription, invoice, delivery, drug utilization review, and any frequency-of-use documentation immediately. Incomplete responses are often treated the same as missing documentation. Don't assume a small discrepancy will be overlooked.

Auditors will communicate audit findings to various regulatory oversight agencies if irregularities are not satisfied. Reponses must be thorough and with foresight of downstream impacts.

Document overrides and exceptions at the moment they happen. Every early refill, quantity override, or dispense-as-written change should have a written explanation in the patient record at the time of dispensing, not reconstructed after the fact. Auditors discount explanations that appear to have been added retroactively.

Build prior authorization documentation into your own workflow, even when a third party handled it. If a vendor or prescriber's office obtained the PA, get a copy into the patient's pharmacy record. PBMs hold the dispensing pharmacy accountable for the claim regardless of who initiated the authorization.

Train staff specifically on high-risk categories. General audit training isn't enough; staff should know the specific rules for diabetic supplies, specialty/GLP-1, prior authorizations, controlled substance red flags, and compound documentation, since each category has different failure points.

Know your state's pharmacy audit protections. Many states have fair-audit laws that limit how far back a PBM can review claims, restrict extrapolation (applying an error rate found in a small sample to a much larger universe of claims), and require detailed findings before recoupment. Understand what protections apply before you're mid-audit, not during it.

Consider periodic outside review. A pharmacy compliance attorney can review your procedures against current PBM contract terms and flag shortcomings before it becomes a finding. This resource is particularly useful if your pharmacy fills a high volume of prescription drug products or medical devices which routinely show up in audit findings.

The bottom line

Diabetic testing supplies, specialty drugs, GLP-1s, high-reimbursement medications, controlled substances, and compounds all draw audit attention for related reasons: high dollar value, complex documentation requirements, or utilization patterns that are easy to check against a claims database. None of the common findings are exotic; they're sourcing verification, days' supply accuracy, correct data entry, NDC precision, prior authorization documentation, dispense-as-written documentation, medical necessity documentation, and paperwork discipline. Pharmacies that build these checks into everyday workflow, and run their own audits before a PBM does, are the ones that come out clean.