Summary: The Centers for Medicare & Medicaid Services modified its policy on surgical or other invasive procedures performed on the wrong body part, effective May 15, 2026. Here's what billing teams need to know before that date.
This CMS wrong-site surgery coverage policy sits at the intersection of patient safety, claims payment, and quality reporting. The Centers for Medicare & Medicaid Services classifies wrong-body-part surgery as a "never event" — a serious reportable event that Medicare will not reimburse under any circumstance. This modification reinforces and updates the billing guidelines governing how facilities and physicians report, adjust, and appeal claims when these events occur. This policy does not list specific CPT or HCPCS codes.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Surgical or Other Invasive Procedure Performed on the Wrong Body Part |
| Policy Code | N/A |
| Change Type | Modified |
| Effective Date | May 15, 2026 |
| Impact Level | High |
| Specialties Affected | Surgery, orthopedics, neurosurgery, urology, ophthalmology, ENT, and any surgical specialty performing lateralized or site-specific procedures |
| Key Action | Audit your charge capture and claims adjustment workflows for wrong-site surgical events before May 15, 2026 |
CMS Wrong-Body-Part Surgery Coverage Policy: Medical Necessity and Payment Exclusions 2026
CMS does not recognize wrong-site surgery as a medically necessary service. That's the core of this coverage policy, and it hasn't changed. What gets updated in modifications like this one are the specific billing guidelines, reporting requirements, and claims handling procedures that surround the event.
Under Medicare's never event framework, a surgical or other invasive procedure performed on the wrong body part — wrong side, wrong organ, wrong level — is non-reimbursable. The facility cannot bill the patient. The physician cannot bill the patient. CMS expects the provider to absorb the cost entirely.
The real issue here is what happens after the event. Your billing team faces a chain of decisions: how to code the original claim, whether to submit it at all, how to handle any related claims for corrective procedures, and how to document everything for audit purposes. Getting any of those steps wrong creates downstream claim denial risk and potential compliance exposure.
Prior authorization is not applicable to never events — there's no pathway to get a wrong-site surgery approved in advance. The medical necessity determination is categorical: this procedure, on this site, was not the intended or appropriate procedure, so Medicare will not pay. The question isn't whether to seek prior auth. The question is how to handle the claim correctly after the fact.
CMS Wrong-Body-Part Surgery Exclusions and Non-Covered Indications
CMS treats wrong-body-part surgery as a hard exclusion. There are no circumstances under which a claim for the incorrect procedure on the incorrect site qualifies for reimbursement.
The exclusion extends broadly. Wrong body part includes wrong laterality (left knee instead of right knee), wrong spinal level, wrong organ in a paired-organ system, and wrong site on a given structure. If your surgical specialty regularly performs lateralized or level-specific procedures — orthopedics, neurosurgery, ENT, ophthalmology — this coverage policy is directly relevant to your claims environment.
The exclusion also covers related services provided during the same operative session when those services were only necessary because of the wrong-site error. CMS does not allow facilities to unbundle and recover reimbursement for individual components of a procedure that shouldn't have happened at all. If your billing team is submitting modifier-adjusted claims to recover partial reimbursement for a never event, stop and loop in your compliance officer before May 15, 2026.
Corrective procedures — the subsequent surgery to perform the originally intended operation on the correct site — are a separate matter. Those claims carry their own medical necessity documentation requirements. They are generally billable when properly supported. But the initial wrong-site procedure is not, and bundling those claims creates serious audit risk.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Surgical procedure performed on the correct body part, intended site, correct laterality | Covered (when medically necessary) | Procedure-specific CPT codes | Standard medical necessity documentation required |
| Surgical procedure performed on the wrong body part / wrong side / wrong site | Not Covered | N/A — this policy does not list specific codes | Never event; patient cannot be billed; facility absorbs cost |
| Corrective procedure to perform the originally intended surgery on the correct site | Covered (when medically necessary) | Procedure-specific CPT codes | Requires clear documentation linking corrective procedure to original error; separate claim |
| Related services rendered during wrong-site operative session | Not Covered | N/A | CMS does not allow partial reimbursement for components of a never event procedure |
This policy does not list specific CPT, HCPCS, or ICD-10 codes. The coverage determinations above are derived from CMS's never event framework as applied to this policy.
CMS Wrong-Body-Part Surgery Billing Guidelines and Action Items 2026
| # | Action Item |
|---|---|
| 1 | Audit your claims adjustment workflow before May 15, 2026. If your facility or practice has any open or pending claims that touch a wrong-site surgical event, review each one against this updated coverage policy before the effective date. Pay specific attention to modifier usage and any partial billing strategies. |
| 2 | Do not bill the patient for a never event. This is a hard prohibition under Medicare's policy. Wrong-body-part surgery billing cannot be passed to the Medicare patient as a patient responsibility balance. Doing so is a compliance violation, not just a claim denial issue. Your billing team should confirm that your patient financial services workflows flag these cases automatically. |
| 3 | Train your surgical scheduling and pre-op teams on the upstream prevention angle. CMS's never event policy creates a financial consequence that incentivizes prevention. The Joint Commission's Universal Protocol — site marking, time-out procedures, pre-operative verification — directly reduces the frequency of events that trigger this coverage exclusion. Your compliance officer should connect the billing exposure to the clinical prevention workflow. |
| 4 | Document corrective procedures separately and completely. When a corrective surgery is performed after a wrong-site event, that claim needs its own medical necessity documentation. The operative note must clearly describe the corrective nature of the procedure and reference the original event. Sloppy documentation here is the fastest path to a claim denial or a Medicare audit flag. |
| 5 | Review your hospital's internal cost reporting process for never events. Since CMS will not reimburse wrong-site surgeries, the cost hits your facility's operating budget directly. Your revenue cycle team should have a clear process for capturing that cost, reporting it through appropriate quality and incident channels, and tracking it for internal risk management purposes. If that process doesn't exist, build it before May 15, 2026. |
| 6 | Check your malpractice and liability insurance coordination. Wrong-site surgery often triggers concurrent malpractice proceedings. Your billing team needs to understand how a liability settlement or payment interacts with any Medicare claims for related services — including the corrective procedure. If you're not sure how this applies to your facility's situation, talk to your compliance officer and legal counsel before the effective date. |
| 7 | Verify your EHR and billing system flags never events at the charge capture stage. The best time to catch a wrong-site surgery claim is before it goes out the door, not after a claim denial comes back. Your charge capture system should have a mechanism to flag operative claims for human review when incident reports or never event documentation exists in the patient record. |
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
CPT, HCPCS, and ICD-10 Codes for Wrong-Body-Part Surgery Under This Policy
This policy does not list specific CPT, HCPCS, or ICD-10 codes. That is not unusual for a never event policy — the prohibition applies across all surgical and invasive procedures regardless of the specific code billed.
What This Means for Your Code-Level Billing
The absence of a code list means your billing team cannot rely on a simple code-match exclusion to catch these claims. The wrong-site determination is clinical, not code-based. A claim for CPT 27447 (total knee arthroplasty) looks identical whether it was performed on the correct knee or the wrong knee. The flag has to come from clinical documentation review, not from the charge master.
This is the central operational challenge with never event billing. Your compliance and billing teams need a process that connects clinical incident reporting to the claims workflow — not just a code scrubber.
ICD-10-CM Codes to Be Aware Of
While this policy does not list specific ICD-10 codes, the ICD-10-CM system does include codes for reporting complications related to surgical errors. Y65.51 (Performance of wrong procedure on correct patient) and related codes in the Y65 category are used to document these events in the medical record. These codes should appear in the incident documentation and potentially in claims for corrective procedures, depending on your facility's coding protocols and your MAC's guidance.
Confirm the appropriate use of Y65-range codes with your coding team and compliance officer. Regional Medicare Administrative Contractor guidance may affect how and when these codes are included on claims.
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