CPT code 27487 – Revision total knee arthroplasty billing guide

Key takeaways

CPT code 27487 applies when the femoral component and the entire tibial component are removed and replaced. An insert-only exchange does not qualify.

An LT or RT laterality modifier is mandatory on every line. Missing it is the leading denial trigger for 27487 claims.

Claims linked solely to T84.84XA (implant pain) are frequently denied without a supporting mechanical failure code such as T84.012A or T84.032A.

Pabau’s claims management software tracks orthopedic procedure codes, modifier requirements, and denial patterns across payer types in one workflow.

CPT code 27487: Official descriptor and clinical scope

CPT code 27487 is defined by the American Medical Association as: Revision of total knee arthroplasty, with or without allograft; femoral and entire tibial component. The critical phrase is “entire tibial component”. The tibial tray, or baseplate, must be removed and replaced, not just the polyethylene insert sitting on top of it.

The code covers both cemented and cementless revision constructs. Allograft augmentation is included within the procedure when performed, so it does not require a separate code when billed under 27487.

What the revision surgery involves

Revision total knee arthroplasty is substantially more complex than a primary knee replacement. The surgeon removes failed implants from bone weakened by loosening, infection, or periprosthetic fracture, then reconstructs the joint with a new implant system. The operative note must reflect every step to support CPT code 27487 at audit.

• Implant removal: the existing femoral component is extracted from the distal femur, and the tibial tray and baseplate are removed from the proximal tibia
• Bone preparation: necrotic or infected tissue is debrided, and bone defects are assessed for size and structural integrity
• Allograft augmentation: where structural bone loss is present, a bone allograft restores the joint line before implant seating. This is captured within 27487 rather than coded separately
• Component placement: new femoral and full tibial components are cemented or press-fit into position, and a new polyethylene insert is seated on the tibial baseplate
• Laterality documentation: the operative note must state whether the left or right knee was operated on, which is what supports the modifier on the claim

The billing record for this procedure begins in the operating room. An operative report that does not specify which tibial components were removed and replaced turns a correctly performed surgery into a denied claim.

CPT 27487 vs CPT 27486: Choosing the right revision code

The decision between 27486 and 27487 turns on one question. Was the tibial baseplate removed and replaced?

If yes, use 27487. If only the femoral component was revised and the baseplate stayed in place, use 27486. If only the polyethylene insert was exchanged, neither code applies. The chart below carries that single question through to each code.

The American Academy of Orthopaedic Surgeons reports single-stage revision TKA with all components replaced under CPT code 27487. That holds whether one knee or both are operated on in the same session.

Which modifiers to append, and when

Modifier selection for this code follows the standard rules for major joint arthroplasty. Laterality is not optional. Missing LT or RT is the single most common denial cause across all payer types, per AAPC coding guidelines.

Accepted ICD-10 diagnosis codes

Payers require a diagnosis that objectively supports the medical necessity of full-component revision, so the ICD-10 link decides whether the claim pays. Pain alone rarely passes scrutiny. The ICD-10-CM code index lists each T84 subcategory in full, which helps when the documented failure mode is not in the table below.

AAPC forum data confirms a consistent denial pattern when 27487 is submitted with T84.84XA as the only diagnosis. Pain is a symptom, not a structural indication for full-component revision.

Payers expect a mechanical failure code as the primary diagnosis. That means T84.012A, T84.023A, T84.032A, or T84.59XA, with T84.84XA listed as secondary when relevant. Preoperative imaging supporting loosening or component failure belongs in the medical record, and the operative report should reference it.

Medicare reimbursement and fee schedule

This code carries a 90-day global surgery period under Medicare, classified as a “090” global. All postoperative care within 90 days of the procedure date is included in the surgical fee. Separate E/M visits inside that window need modifier 24 or modifier 79 to be separately billable.

Use the CMS Physician Fee Schedule lookup tool to retrieve current 2026 payment rates for your Medicare Administrative Contractor locality. Rates vary by geographic practice cost index. As a reference baseline:

Underpayments on revision claims surface during reconciliation rather than at submission. Practice management software like Pabau matches each posted payment against the contracted rate and flags the variance for review.

Its Claim.MD clearinghouse integration routes 27487 claims to thousands of payers, with real-time eligibility and electronic remittance processing built in.

Prior authorization requirements by payer type

Authorization requirements differ substantially by payer type. Submitting a 27487 claim without the required prior authorization is a preventable denial. It cannot be resolved on appeal, because payers rarely waive the requirement retroactively.

• Traditional Medicare FFS: no prior authorization is required under the fee-for-service program. The procedure must still meet CMS coverage criteria, and the medical record must support the indication.
• Medicare Advantage plans: most MA plans require prior authorization for revision TKA. Requirements vary by plan and contract year, so verify with the plan before scheduling surgery.
• Commercial payers: the large majority of commercial insurers require PA for revision knee arthroplasty. Turnaround runs from 3 to 15 business days, depending on the payer’s clinical review process.
• Workers’ compensation payers: WC billing rules and fee schedules are state-specific. Authorization requirements, approved code sets, and reimbursement amounts vary by jurisdiction, so verify with the state WC board and the individual payer.

Confirm eligibility and authorization status before the patient’s surgery date. For Medicare Advantage, request the authorization in writing and keep the reference number with the claim file. Build a pre-surgical authorization checkpoint into the scheduling workflow for every 27487 case, whatever the payer.

Common denial reasons and how to prevent them

Most 27487 denials fall into a handful of repeating patterns. Addressing them at the point of claim creation avoids the delay of rework and appeal. Practices that check modifier, diagnosis, and authorization status before the claim leaves the building see materially fewer first-pass denials.

Reviewing denials in aggregate rather than case by case shows which patterns run practice-wide and which are one-offs. A structured denial management process for orthopedic codes cuts rework time and stops repeat denials on the same root cause.

Documentation the operative report must contain

The operative report is the primary audit document for this code. Payers routinely request it on post-payment review, and a deficient op note can trigger full repayment of an already-processed claim. The note must contain specific elements, not simply confirm that a “revision knee replacement” was performed.

• Component removal confirmed: explicit statements that the femoral component was removed from the distal femur and the baseplate from the proximal tibia
• Laterality stated: left or right knee identified, which is what supports the LT or RT modifier on the claim
• Allograft documented: where bone allograft was used, the type (structural or morcellized), the source, and how it reconstructed the bone defect
• Implant details: manufacturer name and catalog numbers for the new femoral and tibial components, which many payers require for implant billing reconciliation
• Medical necessity rationale: the preoperative diagnosis, such as loosening documented on X-ray or infection confirmed by culture, referenced in the op note as the indication
• New components placed: an explicit statement that new femoral and tibial components, including tray, baseplate and polyethylene insert, were cemented or press-fit into position

Capture these elements at the point of service rather than reconstructing them when a payer requests records. A pre-billing checklist built from the list above is what keeps a post-payment review from turning into a repayment.

NCCI edits and bundling rules

The National Correct Coding Initiative edits for 27487 bundle several codes that cannot be billed separately on the same claim. The most common conflict comes from coding a tibial insert exchange alongside 27487. When the full tibial component is replaced, the polyethylene insert is included, so there is no separate insert exchange to bill.

• Do not bill tibial insert-only exchange codes on the same claim as 27487
• Imaging ordered as part of the surgical procedure is typically bundled. Bill imaging separately only where it was a distinct, medically independent service
• Review the CMS NCCI Policy Manual for musculoskeletal codes annually, since edits update quarterly and bundling rules can change
• Where an edit carries a modifier indicator of “1”, appending modifier 59 may allow separate billing. Use it only where the two services were genuinely distinct and separately documented

Bilateral knee revision: Coding and billing rules

When both knees are revised in the same operative session, bill two separate line items for 27487. One carries modifier LT and the other carries modifier RT. Do not use modifier 50 for this code under Medicare.

Medicare applies a 50% reduction to the lower-value procedure on the second line. The record must establish independent medical necessity for revising both knees at once.

The operative report and preoperative notes should address why a same-session bilateral procedure was clinically appropriate rather than a staged one. Most commercial payers follow the same two-line approach, though reimbursement rules vary by contract.

How Pabau keeps revision claims clean before they reach the payer

In most orthopedic billing teams, a revision claim is checked in three places at once. One person confirms the modifier, another chases the authorization reference, and the operative note sits in a separate system. A missing LT costs a week of rework and a resubmission.

Pabau’s claims management software holds the procedure code, the diagnosis link, the modifier rule, and the payer’s authorization requirement against the same patient record. Claims are scrubbed against those rules before submission, so a 27487 line missing its laterality modifier is caught inside the practice.

Billing teams then spend their time on the denials that need judgment, instead of the ones a checklist would have caught. Payment posting and remittance reconciliation run in the same place, so an underpaid revision claim becomes visible the week it lands.

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Pabau connects your procedure codes, modifier rules, and payer requirements in one place. See how orthopedic practices use Pabau to reduce denials and accelerate reimbursement.

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Conclusion

The difference between 27486 and 27487 comes down to one sentence in the operative note. Where the surgeon states that the tibial tray came out and a new one went in, the higher code is defensible at audit. Where the note is vague, the claim is rarely worth appealing.

Three things account for most of the loss on these claims: the laterality modifier, the primary diagnosis, and the authorization reference. All three are checkable before the claim leaves the practice, and an appeal cannot recover what was missing at submission. Book a demo to see how Pabau catches all three on orthopedic claims before they go out.

Continue your research

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Want a complete guide to preventing claim rejections before they happen? Clean claim best practices covers the elements every surgical claim needs to pass first-pass adjudication.

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