OIG Completed a Medicare Billing Audit in July 2026: What Your Practice Needs to Check Now

What Is the OIG Medicare Billing Overpayment Audit?

As of July 2026, the HHS Office of Inspector General completed its audit of Medicare Part B claim lines where federal payments exceeded the provider’s billed charges (Project A-07-24-04138). This audit targets billing errors that result in overpayments to healthcare providers, and previous rounds have recovered millions of dollars from practices that submitted claims with incorrect units of service, wrong HCPCS codes, or insufficient documentation. For practices billing Medicare Part B, the completion of this audit signals that recoupment activity tied to its findings is next.

• Previous audits recovered millions. Earlier iterations of this same audit identified overpayments ranging from $2 million to $7 million per Medicare Administrative Contractor jurisdiction, driven by the same recurring billing errors.
• The errors are preventable. The most common deficiencies found in prior audits were incorrect units of service, HCPCS codes that did not match the procedure performed, and claims lacking supporting documentation.
• Recoupment follows audit completion. Once OIG publishes its findings, Medicare Administrative Contractors issue recovery demands to affected providers, and the 60-day repayment clock starts.

What This Audit Covers

The OIG audit (Project A-07-24-04138) examines Medicare Part B claim lines where the amount CMS paid exceeded the amount the provider actually charged. Under normal Medicare Part B payment rules, reimbursement is based on a fee schedule, prospective payment system, or other standardized method, not on the provider’s billed charges. In most cases, a provider’s charges exceed what Medicare pays. When the reverse happens and Medicare pays more than the provider billed, it almost always indicates a billing error that produced an overpayment.

The audit was announced in August 2024 and completed on July 21, 2026. It covers services including physician services, outpatient hospital services, drugs and biologicals, durable medical equipment, and outpatient therapy services. Prior OIG audits using this same methodology have consistently found that a majority of claim lines where payments exceeded charges contained billing errors. The deficiency categories are remarkably stable across audit cycles: incorrect units of service, HCPCS codes that do not reflect the actual procedure, packaged services billed separately, and claims without adequate supporting documentation.

One question we hear constantly from practice managers is whether their billing team would even notice a payment that came in higher than expected. In many cases, the answer is no. When a payment posts above the expected amount, it looks like good news. The billing team moves on. But that overpayment is sitting in your revenue as a liability that OIG has now quantified.

Does This Audit Affect Private Practices?

Yes. The audit covers all Medicare Part B claim types, which means any provider or practice that bills Medicare Part B for covered services is within scope. This includes physician offices, outpatient clinics, therapy practices, imaging centers, and any facility or provider billing for Part B drugs, DME, or outpatient services. The audit is not limited to hospitals or large health systems.

The risk is proportional to claim volume and coding complexity. Practices that bill high volumes of injectable drugs (where unit counts frequently cause errors), surgical procedures with multiple HCPCS codes on the same date of service, or outpatient therapy services with time-based billing are statistically more likely to have claim lines where payments exceeded charges. Across the billing companies we vet at Billing Service Quotes, the practices most often flagged for this type of issue are those relying on in-house billing staff who do not have time to reconcile posted payments against expected reimbursement.

For practices already working with an experienced medical billing company, payment reconciliation is typically built into the posting workflow. The billing team catches overpayments during the posting process, investigates the cause, and corrects the claim before it becomes a recoupment target. Practices handling billing internally often lack this checkpoint.

Why Payments Exceed Charges

Understanding the mechanics helps you check your own claims. Medicare Part B payments are calculated using fee schedules and relative value units, not provider charges. The billed charge on the claim is supposed to represent the provider’s standard rate for the service. The payment is whatever the fee schedule says, regardless of what was charged. When the payment exceeds the charge, the most common causes are:

• Incorrect units of service. A provider bills 1 unit but the claim processes at a higher unit count due to a data entry error. This is the single most frequent deficiency found in prior OIG audits of this type.
• Wrong HCPCS or CPT code. The code on the claim does not match the procedure actually performed. A higher-paying code is submitted in error, and the fee schedule payment for that code exceeds what the provider intended to charge for the actual service delivered.
• Packaged services billed separately. Services that should be bundled under a single payment are broken out as individual line items, and the combined payment for the separate lines exceeds the single bundled payment.
• Missing or insufficient documentation. The claim pays, but the medical record does not support the service billed. Without documentation, the payment is considered unsupported and subject to full recoupment.

How Should Practices Prepare for Recoupment Activity?

OIG audit completion means findings are being compiled and recovery demands will follow. These steps protect your practice now.

• Run a payment-versus-charge reconciliation report. Pull all Medicare Part B claim lines from the last 24 months where the payment exceeded the billed charge. Your practice management system should be able to generate this report. If it cannot, your billing company should.
• Review flagged lines for unit count accuracy. For every claim line where payment exceeded charges, verify that the units of service billed match what was actually documented and delivered. Injectable drugs and time-based therapy codes are the most error-prone categories.
• Check HCPCS code accuracy against the operative or visit note. Confirm that the procedure code on the claim matches the procedure described in the medical record. If there is a mismatch, correct the claim proactively.
• Verify supporting documentation exists for every flagged line. If the medical record does not support the service billed, the payment is unsupported. Unsupported payments are recouped in full, not adjusted.
• Contact your MAC to self-report and refund identified overpayments. Under the 60-day rule, providers who identify overpayments must report and return them within 60 days. Proactive refunds reduce penalty exposure.
• Engage your billing company or consider outsourcing if you bill internally. A billing company with proper payment posting processes catches these discrepancies as part of the daily workflow, not after an OIG audit forces the issue.

Mistakes That Increase Recoupment Risk

Providers often come to us after a recoupment demand has already arrived, and the patterns are consistent. Here are the mistakes that put practices at the highest risk.

• Treating overpayments as windfalls. When a payment comes in higher than expected, some billing teams simply post it and move on. That overpayment is not extra revenue. It is an error that CMS or its contractors will eventually identify and demand back, often with interest.
• Not reconciling posted payments against fee schedule expectations. If your billing team does not compare every payment to the expected reimbursement for the code and units billed, overpayments will accumulate undetected. This reconciliation step is standard in professional billing operations but often skipped in under-staffed in-house billing departments.
• Ignoring the 60-day repayment rule. Once a provider identifies or should have identified an overpayment, the False Claims Act gives them 60 days to report and refund it. Failure to do so can convert a billing error into a fraud allegation. This is not a hypothetical risk. OIG has used the 60-day rule as the basis for enforcement actions against providers who delayed repayment.
• Assuming only hospitals get audited. The OIG audit covers all Medicare Part B providers. Small practices, solo practitioners, and specialty groups are all within scope. The dollar amounts per claim line may be smaller, but the audit methodology does not exclude anyone.

In-House Billing vs. Outsourced Compliance

The overpayment audit highlights a specific capability gap. The question for practice managers is whether their current billing setup catches these errors before federal auditors do.

In our experience matching providers with billing partners, the practices that are best protected against recoupment activity are those whose billing company runs payment reconciliation as a daily function, not an annual exercise. If your current billing process does not include this step, the risk is not theoretical. It is quantified in the OIG audit that just completed. For practices evaluating whether to outsource, understanding how billing costs compare to the cost of a recoupment demand puts the decision in financial terms.

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