CPT code 27132 – Conversion total hip arthroplasty billing guide

Key takeaways

CPT code 27132 covers conversion of prior hip surgery to total hip arthroplasty, not a first-time primary replacement.

The operative note must document existing hardware, the prior procedure, and placement of both acetabular and femoral components.

Laterality modifiers LT or RT are required on Medicare claims for a lateralized hip procedure.

Modifier 58 applies when the conversion is a planned second stage after a periprosthetic joint infection spacer.

Practice management software like Pabau keeps the authorization number and prior operative report on the claim record.

CPT code 27132: official descriptor and procedural definition

The AMA CPT code set gives 27132 this official descriptor: conversion of previous hip surgery to total hip arthroplasty, with or without autograft or allograft. The word “conversion” carries the weight. It tells the payer that hardware was already in the hip, and that the surgeon built a complete ball-and-socket joint around it. That finished construct holds both an acetabular cup and a femoral stem.

The descriptor does not restrict 27132 to one type of prior procedure. Candidates include a patient with a hemiarthroplasty, a failed fixation device such as a dynamic hip screw or intramedullary nail, or a resurfacing prosthesis. What matters for coding is that the current surgery places a full total hip arthroplasty construct where an incomplete or non-THA implant existed before.

The descriptor ends with “with or without autograft or allograft.” Bone grafting to rebuild an acetabulum damaged by prior surgery is therefore bundled into 27132. Billing a separate bone graft code alongside 27132 will typically trigger a bundling edit. Bundling edits like this are easier to catch when the charge is built next to the note. Practice management software like Pabau puts tools for orthopedic billers in the same system as the patient record and the operative note.

What the procedure involves: clinical overview

A coder does not need surgical training to document 27132 correctly. Knowing what the operative note should describe helps you catch incomplete documentation before the claim is built. The billing workflow for an orthopedic conversion starts at the operative note rather than the charge sheet.

A hemiarthroplasty-to-THA conversion runs in five steps:

• Expose the hip and remove the existing femoral head implant.
• Prepare or preserve the femoral canal, depending on the condition of the stem.
• Prepare the acetabulum, which was left native at the original hemiarthroplasty.
• Insert the acetabular cup and liner.
• Reduce the joint with a femoral head trial, then seat the final femoral component.

The acetabular preparation is the defining step. A hemiarthroplasty has no cup, so adding one is what makes the surgery a conversion.

In a second-stage reimplantation after periprosthetic joint infection (PJI), the first stage removed the infected hardware and placed an antibiotic-loaded spacer. At the second stage, the spacer is removed, the joint is debrided, and a new total hip arthroplasty construct is implanted. This scenario can support 27132, but only when the pre-infection implant was not a complete THA.

27132 vs 27130 vs 27134: choosing the correct code

Selecting the wrong code from the hip arthroplasty family is the most frequent coder error on these claims. The decision hinges on two questions. Does prior hip hardware exist, and is the surgeon placing a whole construct or revising part of one? The decision tree below runs both questions in order.

The distinction between 27132 and the 27134 to 27138 revision codes is the nature of the prior implant. If the patient previously had a complete THA, both cup and stem, later replacement of components falls under the revision family. If the prior implant was less than a complete THA, the surgery that creates one is a conversion, coded 27132. When the hip was native before this surgery, the claim belongs on 27130 instead.

Documentation the operative note must carry

Payers routinely deny 27132 claims over missing paperwork rather than clinical ineligibility. The operative note and supporting records have to establish what was in the hip before, what the surgeon did, and why. Pull the claim package from these sources.

• Prior operative report: The report from the original hip surgery (hemiarthroplasty, ORIF, resurfacing) confirming the type of hardware placed. If unavailable, implant stickers or radiology reports confirming implant type are acceptable substitutes with a brief explanation.
• Implant stickers or device records: Labels from the acetabular cup, liner, femoral head, and femoral stem placed at the current surgery. These prove a complete THA construct was implanted.
• Current operative note elements: Documentation of hardware removal or retention, since a well-fixed femoral stem may be left in place. The note must also cover acetabular preparation and cup insertion, femoral component assessment and exchange, and reduction and closure.
• Imaging: Preoperative radiographs showing the existing implant and the indication for conversion (e.g., pain, instability, femoral head erosion into the acetabulum).
• For PJI second-stage cases: Inflammatory marker results (ESR and CRP) and aspiration results from the period between stages. Add the original explantation note confirming spacer placement, plus intraoperative culture results from the current surgery.
• Diagnosis codes and LCD alignment: The ICD-10 code selected must appear on the payer’s covered diagnosis list (see the next section). A mismatch between the operative note’s documented indication and the ICD-10 code submitted is a common trigger for medical necessity denials.

Accepted ICD-10-CM diagnosis codes for medical necessity

Medicare coverage for CPT code 27132 runs through LCD L34163, Total Hip Arthroplasty, which sets out the indications that establish medical necessity. That policy replaced the retired L36573 on November 6, 2025. The ICD-10-CM codes below are among those most commonly accepted, and the ICD-10-CM code reference carries the full descriptors. Check your own MAC’s covered-diagnosis list before submission, since jurisdictions differ.

Always confirm that the selected primary ICD-10 code is on the payer’s covered list for 27132 before submission. Z96.64x codes function as secondary codes and do not establish medical necessity on their own. Each must accompany a primary diagnosis code that justifies the procedure.

Modifiers required with CPT 27132

Missing or incorrect modifiers account for a significant share of 27132 denials. The table below covers the modifiers most commonly required or encountered on these claims.

For commercial payers, laterality modifier requirements vary. Some apply LT or RT to musculoskeletal codes, and others do not. Check the payer’s own policy, along with eligibility and modifier rules, before the claim is built.

Medicare reimbursement and 2026 fee schedule

The CMS Medicare Physician Fee Schedule sets payment rates for CPT code 27132 annually. For 2026, 27132 carries 45.03 total relative value units (RVUs), which pays about $1,504.04 nationally. Geographic Practice Cost Index (GPCI) values move that figure up or down in every locality, so pull your own rate from the CMS lookup.

The 2026 RVU components behind that figure are:

The 2026 conversion factor is $33.4009. Clinicians who qualify as advanced alternative payment model participants are paid on a slightly higher factor of $33.5675.

Payability in an ambulatory surgery center (ASC) depends on the CMS ASC Covered Procedures List for that year. Hip arthroplasty has moved on and off that list with regulatory updates, so check CMS data before you assume facility payment.

Global surgical period and post-op billing rules

CPT code 27132 carries a 90-day global period, consistent with major musculoskeletal surgical codes. The global surgical package includes all routine post-operative care furnished by the operating surgeon (or their group) within 90 days of the procedure date. Billing separate E/M codes for routine follow-up visits within that window will be denied by Medicare and most commercial payers.

Services that remain separately billable during the global period include:

• Treatment of complications requiring a return to the operating room (use modifier 78 for related, 79 for unrelated procedures)
• E/M visits for a condition or problem entirely unrelated to the hip procedure (use modifier 24 to signal an unrelated service)
• Physical therapy and rehabilitation services provided by a separate therapist or therapy practice (these are not part of the surgical global package)
• Durable medical equipment such as a walker, raised toilet seat, or hip kit, billed separately by the supplier
• Diagnostic imaging ordered by a different physician for an unrelated condition

Orthopedic practices running high arthroplasty volumes need the global period start date tracked from the day of surgery. Build that check into the billing process, so E/M charges inside the 90-day window are caught before they go out.

Prior authorization and payer requirements

Commercial payers almost always require prior authorization for CPT code 27132, and Medicare Advantage plans usually do too. Traditional Medicare (Parts A and B) does not, though LCD L34163 criteria still govern coverage. Either way, document the clinical indication in full before you submit the authorization request.

LCD L34163 lists these conditions as covered indications for THA, which extend to 27132:

• Severe hip joint disease causing pain and disability unresponsive to conservative treatment (documented trial of NSAIDs, physical therapy, and/or corticosteroid injections)
• Radiographic evidence of significant joint space loss, osteophyte formation, or implant failure
• Functional limitation that substantially impairs activities of daily living

Most commercial insurers want the operative plan, preoperative imaging, documentation of conservative treatment failure, and the proposed ICD-10 diagnosis code. Some plans also require functional assessment scores, such as the Oxford Hip Score or HOOS, to establish baseline disability. Capture the authorization number at charge entry and attach it to the claim before it leaves your system.

Common claim denial reasons and how to avoid them

Denials on CPT code 27132 follow a short list of patterns, and most are correctable upstream of submission. Pull your remittance reports and sort them by claim adjustment reason code (CARC) to see which of the categories below is costing you.

• Wrong code selected (27130 submitted instead of 27132): Coders unfamiliar with the prior-surgery history choose the primary THA code. Fix: add a pre-coding checklist that requires review of the prior operative report before assigning any hip arthroplasty code.
• Missing or absent prior authorization number: The auth was obtained but not attached to the claim, or the procedure date fell outside the auth window. Fix: build auth-number capture into the charge-entry workflow with a mandatory field.
• Insufficient documentation of prior hardware: The payer cannot verify that prior hip surgery occurred. Fix: attach the prior operative report or imaging to the claim as an attachment (ANSI 275 or fax per payer policy).
• ICD-10 code not on the covered-diagnosis list: The selected diagnosis code does not map to 27132 under the LCD. Fix: verify ICD-10 code against the MAC’s covered-diagnosis list before submission using the AAPC Codify lookup.
• Missing laterality modifier: LT or RT absent from a Medicare claim. Fix: automate modifier appending in your practice management system for all lateralized musculoskeletal CPT codes.
• Modifier 22 used without adequate documentation: Increased complexity modifier applied but the operative note does not describe the complicating factors in detail. Fix: add a modifier-22 attestation section to your operative note template requiring specific complexity justification.

Coding the second-stage reimplantation after hip infection

The second-stage reimplantation scenario is the most nuanced application of CPT code 27132, and the one that generates the most coder questions. In a two-stage revision for PJI, the first stage removes the infected implant and places an antibiotic-impregnated spacer. The second stage, weeks to months later, removes the spacer and implants a new total hip arthroplasty construct.

Whether 27132 is appropriate for the second stage depends on what was present before the infection developed. Use this decision framework:

• If the infected implant was a hemiarthroplasty: The second-stage reimplantation creates a complete THA where only a partial construct existed, so 27132 may apply. The operative note must record that the prior construct was a hemiarthroplasty, and that this surgery places both components for the first time.
• If the infected implant was a complete THA: The second stage restores a full THA construct that already existed. This is a revision of a prior THA, and the 27134-27138 revision code family applies, not 27132. Review the original implant records carefully.
• Documentation at the second stage: Operative note must describe spacer removal, intraoperative cultures, joint debridement, acetabular and femoral component insertion, and the original implant type. Attach the first-stage operative report.
• Modifier 58 (staged procedure): Use it when the same surgeon performs both stages and the second falls inside the global period of the first. It signals that the second procedure was planned, which protects full payment.

Coding authorities agree that 27132 can apply to a second-stage reimplantation when the pre-infection implant was not a complete THA. Where the prior implant was a full THA, the revision codes govern instead. The determination stays a judgment call, so review the operative note against current AMA guidance before you settle on a code.

How claims management software keeps 27132 claims clean

Most orthopedic billing teams assemble a 27132 claim by hand. The prior operative report sits in a scanned folder, the authorization number lives in a spreadsheet, and the implant stickers are photographed on a phone. A missing piece only surfaces weeks later, on the remittance.

Pabau keeps that material on the patient record, so the prior operative report, the imaging, the authorization number, and the implant details sit together. Claims go out electronically through Claim.MD, which checks each one against payer rules before it reaches the insurer.

The billing team then works from one list instead of three. Its time goes on the handful of 27132 claims that genuinely need a phone call, and rework stops eating the week.

Stop losing 27132 claims to preventable billing errors

Pabau keeps the operative report, the authorization number, and the implant details on one patient record, then submits through Claim.MD. Orthopedic billing teams spend less time rebuilding claims.

Book a demo

Conclusion

27132 claims fail for clerical reasons far more often than clinical ones. A missing laterality modifier, the wrong arthroplasty code, or a prior operative report left out of the package will each do it. All three are fixed upstream, at charge entry, rather than in an appeal.

Pabau submits 27132 claims through Claim.MD, which checks each claim against payer rules before the insurer sees it. To see how that fits an orthopedic billing workflow, book a demo with the team.

Continue your research

Need to understand how clearinghouse submissions work for surgical codes? Medical claims clearinghouse guide explains how 837 transactions, eligibility checks, and ERA reconciliation work together for high-value claims like 27132.

Working through a denial on a 27132 claim? Insurance credentialing for orthopedic practices covers how provider enrollment gaps can trigger denials on surgical claims and how to resolve them upstream.

Want a broader view of the billing lifecycle for surgical procedures? Best medical billing software for US practices compares platforms that handle complex orthopedic claim workflows, including modifier validation and prior auth tracking.

Frequently asked questions