Medicare 60-Day Overpayment Rule 2026

The Refund Clock Starts Sooner Than Most Practices Think

By Yagnesh Dave  ·  September 30, 2026  ·  12 min read

A practice finds out in March that its biller sent 120 claims with the wrong place of service, and Medicare overpaid about $48 on each. That's $5,760, and it feels like a rounding error. But the 60-day overpayment rule starts counting once you know, and a retained $5,760 can turn into a False Claims Act problem with penalties of $14,308 to $28,619 per claim under the current Justice Department table.

The Medicare 60-day overpayment rule is simple to state and easy to get wrong. If you receive money from Medicare you weren't entitled to, you have to report and return it within 60 days of identifying it. Miss that deadline and the overpayment becomes an obligation under federal law.

The rule changed on January 1, 2025, and most practice policies still describe the old version. Here's how the current rule works, how to quantify an overpayment, how credit balances fit in, and what to do on day one.

What the Medicare 60-Day Overpayment Rule Requires

The rule comes from section 1128J(d) of the Social Security Act, passed as part of the Affordable Care Act. CMS wrote the Medicare Part A and Part B version into 42 CFR 401.305. It applies to every provider and supplier that bills Medicare, from a solo physician to a hospital system.

Three requirements matter. You have to report and return an identified overpayment to the Medicare Administrative Contractor (MAC), you have to explain in writing why the money is being returned, and you have to do it within 60 days. A retained overpayment after that point is what the False Claims Act calls an obligation, and knowingly keeping an obligation is a violation on its own. Lawyers call it a reverse false claim.

The lookback period is six years. If you identify an overpayment today, you owe back every related overpayment you received in the past six years, not just the ones from the current year.

Medicare Advantage and Part D have parallel regulations, and the statute reaches Medicaid too. If your practice bills any of them, the same habits apply.

The 2025 Change: "Identified" Now Means "Knowingly"

The old rule said you'd identified an overpayment when you were put on notice, or when you should have determined it through "reasonable diligence." That standard punished practices for what they might have found. It also pushed a lot of them into investigating everything all the time.

CMS replaced it in the CY 2025 Physician Fee Schedule final rule, effective January 1, 2025. Now you've identified an overpayment when you knowingly receive or retain it, and "knowingly" uses the False Claims Act definition: actual knowledge, deliberate ignorance, or reckless disregard of the truth.

That's still a low bar. Ignoring a pattern in your own denial reports doesn't protect you. If your remits show repeated credits and nobody looks, a reviewer can argue deliberate ignorance. What the new standard removes is the argument that you should have known something you had no real reason to question.

Calculating the Overpayment and the Six-Year Lookback

Quantifying the amount is where practices stall. You don't have to pull every claim from six years of records. CMS allows a reasonable methodology, including statistical sampling, as long as it's credible and documented.

Suppose a review of 100 randomly selected claims from the past six years finds 6 overpayments averaging $52. If the population is 1,800 similar claims, a simple extrapolation puts the exposure near $5,600. Your auditor or compliance counsel should confirm the sampling method, but the point is you can estimate and refund without a full-chart review.

Keep the investigation file. If anyone asks later, you'll want dated proof that you started promptly, used a sound method and refunded on time.

Credit Balances: When They Become a Refund Obligation

A credit balance is an accounting entry. It shows that a patient account holds more payments than charges. It isn't automatically an overpayment to Medicare, and it isn't automatically yours to keep either.

Every credit has a source. It might be a duplicate payment from the same payer, a primary and a secondary payer who both paid as primary, a patient who paid a copay and then had the claim adjusted, or a claim adjusted after payment because of a coding fix. Trace each credit to the payer that paid it and decide whether the money goes back to Medicare, another payer or the patient.

Patient credits carry another rule. After a patient's balance goes to zero, any leftover money generally has to be refunded. If you can't find the patient, most states treat the money as unclaimed property and expect you to turn it over after a dormancy period, usually between one and five years. Don't let old credits sit in the ledger, because they aren't yours.

Here's the practical test. If your aging report shows credits older than 60 days that nobody has worked, that's the first place a reviewer will look.

Where Overpayments Come From in Real Practices

Most of them are boring. That's why they last.

• Duplicate payments from a resubmitted claim that wasn't caught as a duplicate.
• Place of service errors that pay the non-facility rate for a facility visit.
• Coding errors like a level 5 visit that the note only supports as a level 4.
• Services after death or disenrollment where eligibility changed.
• Incident-to and supervision errors where the rules weren't met.
• Modifier misuse that bypassed an NCCI edit and paid a bundled service.
• Medicare as secondary payer when another plan should have paid first.

A 200-claim overpayment at an average of $75 is $15,000. A practice that finds it within 60 days returns $15,000. A practice that finds it and sits on it for a year risks penalties that dwarf the principal.

OIG, DOJ and CMS Audit Exposure for Overpayments

Auditors don't need a whistleblower to find these. CMS's fiscal year 2025 data puts the Part B provider improper payment rate at 8.44%, or $9.62 billion, and insufficient documentation drove roughly 53% of improper payments across Medicare fee-for-service. Every one of those improper payments is a potential overpayment sitting in somebody's ledger.

On the enforcement side, the Department of Justice recovered more than $6.8 billion under the False Claims Act in fiscal year 2025, the largest single-year total on record, and more than $5.7 billion of it involved health care. A record 1,297 qui tam suits were filed that year. Qui tam means a whistleblower filed on the government's behalf, and your own billers, coders and former employees are the most common source.

The Office of Inspector General audits Part B on a rolling basis and publishes its priorities in the Work Plan. When it finds overpayments, its standard recommendation is to have CMS recover the amounts inside the reopening period and to have the provider look for and return similar overpayments under the 60-day rule. Recovery auditors generally look back three years from the payment date.

Frequently Asked Questions About the 60-Day Overpayment Rule

How long do I have to return a Medicare overpayment?

You have 60 days from the date you identify the overpayment. Under the rule that took effect January 1, 2025, you identify it when you knowingly receive or retain it. If you open a timely, good-faith investigation into related overpayments, the deadline is suspended for up to 180 days.

How far back do I have to look for overpayments?

Six years from the date the overpayment was received. That lookback period applies to Medicare Part A and Part B overpayments under 42 CFR 401.305.

Is a credit balance the same as an overpayment?

Not always. A credit balance is an accounting entry that shows you hold more money than you billed. It becomes a refund obligation when the money belongs to Medicare, another payer or the patient, so each credit needs to be traced to its source.

What happens if I keep an overpayment past the deadline?

The retained overpayment becomes an obligation under the False Claims Act. The current per-claim penalty range in the Justice Department's inflation table is $14,308 to $28,619, plus up to three times the government's damages.