CPT code 28298 – Hallux Valgus Correction

Key takeaways

CPT 28298 requires an osteotomy of the great toe’s proximal phalanx, and without one a different hallux valgus code applies.

Sesamoidectomy is included in 28298 when performed at the same session and can’t be billed separately.

A chevron plus an Akin osteotomy on the same toe is a double osteotomy, reported with 28299 rather than 28296 plus 28298.

Medicare and most commercial payers expect an RT or LT modifier that matches the laterality of the ICD-10 code.

Practice management software like Pabau submits your coded 28298 claims through Claim.MD and tracks their status and remittance.

CPT code 28298: Definition and clinical description

CPT code 28298 is a surgical code in the musculoskeletal section of the AMA CPT code set. It sits within the repair, revision, and reconstruction procedures on the foot and toes. It describes correction of hallux valgus (bunionectomy) with a proximal phalanx osteotomy by any method, plus sesamoidectomy when performed. What sets 28298 apart is the osteotomy site. The surgeon makes the cut in the proximal phalanx of the great toe, not in the first metatarsal.

The “when performed” language covering sesamoidectomy matters for billing. It means the code already includes sesamoid removal at the same operative session. As a result, billing it as a separate line is unbundling and triggers a National Correct Coding Initiative (NCCI) edit denial.

CPT 28298 vs 28296 vs 28299: Choosing the right hallux valgus correction code

The choice between CPT codes 28296, 28298, and 28299 depends on where the surgeon performs the osteotomy and how many osteotomies there are. All three correct the same deformity, but each describes a different surgical approach. Pick the code from the operative report, never from habit.

When a surgeon pairs a chevron osteotomy of the first metatarsal with an Akin osteotomy of the proximal phalanx, the combination is a double osteotomy. Report it with 28299 rather than billing 28296 and 28298 together. The chart below maps each documented finding to its code, so confirm the operative note names every osteotomy site first.

Procedure overview: What the surgery involves

CPT code 28298 covers a multi-step correction of hallux valgus, and the operative report must reflect each step. Coders who know the surgical sequence can confirm faster that the documentation supports the code.

1. Medial incision and exposure: The surgeon opens the medial aspect of the first metatarsophalangeal (MTP) joint.
2. Medial eminence resection: The surgeon resects the prominent medial eminence of the first metatarsal head to reduce the bunion prominence.
3. Proximal phalanx osteotomy: The surgeon makes a closing-wedge or other osteotomy cut at the base of the great toe’s proximal phalanx to correct the residual valgus deformity. This is the defining surgical element for 28298.
4. Fixation: The surgeon stabilizes the osteotomy with internal fixation (screws, staples, or wire), by any method per the descriptor.
5. Sesamoidectomy when indicated: If sesamoid pathology is present, the surgeon removes one or both sesamoid bones at the same session. CPT 28298 captures this, so coders don’t bill it separately.
6. Closure: The surgical team completes wound closure and dressing, and the patient typically goes home in a post-operative shoe or cast boot.

The operative report must name the proximal phalanx as the osteotomy site and document the fixation method. A note that only describes medial eminence resection, with no phalangeal osteotomy, won’t support 28298. That scenario maps to a simple exostectomy code instead.

Documentation requirements for CPT 28298

For foot surgery, billing compliance starts with the operative report. For CPT 28298, the documentation must confirm several elements that payers check on post-payment review.

• Hallux valgus diagnosis: The pre-operative and post-operative diagnosis must match a supportive ICD-10 code (M20.11, M20.12, or M20.10).
• Proximal phalanx osteotomy: The note must name the phalanx explicitly as the osteotomy site, not just reference “bunionectomy.”
• Fixation method: Document what hardware or technique the surgeon used to stabilize the osteotomy cut.
• Sesamoidectomy status: State explicitly whether the surgeon performed a sesamoidectomy. If it was, note the reason (sesamoid pathology, fibrosis, arthritis).
• Laterality: Identify whether the surgeon performed the procedure on the right foot, left foot, or both feet, because correct modifier selection requires it.
• Medical necessity narrative: Many commercial payers require documentation of conservative treatment failure (orthotics, footwear modification, physical therapy) before approving hallux valgus surgery.

Missing any of these elements gives the payer grounds to deny or downcode the claim. A generic operative note template that doesn’t capture the phalangeal osteotomy is a recurring source of avoidable claim losses in podiatric practices.

ICD-10 codes that support CPT 28298

The diagnosis code must match the operative site and carry specific laterality. Avoid the unspecified code (M20.10) on Medicare claims, because payers increasingly cross-check side-specific diagnoses against the CPT modifier. For a left-foot case, the M20.12 reference covers the diagnosis code in more detail.

When the surgeon corrects both feet in the same session, bill CPT 28298 twice, once per foot, with modifiers RT and LT. Some payers prefer modifier 50 on a single line instead. Link each line to its side-specific ICD-10 code.

Modifiers for CPT 28298

Modifier selection is a frequent point of failure for CPT code 28298. The right modifiers depend on laterality, bilateral status, and whether the procedure took unusual extra work.

• Modifier RT / LT: Medicare and most commercial payers require it to indicate right foot (RT) or left foot (LT). Submit the modifier that matches the operative side and the paired ICD-10 code laterality.
• Modifier 50 (Bilateral): Some payers prefer modifier 50 on a single CPT 28298 line rather than two separate lines with RT and LT. Check the payer’s bilateral surgery policy before submission, because Medicare generally expects two separate lines.
• Modifier 22 (Increased Procedural Services): Appropriate when the procedure takes significantly more work than usual. Examples include severe deformity, revision surgery, or extensive scarring from a prior bunionectomy. It needs a detailed operative note and a cover letter explaining the additional work. Routine use raises audit risk.
• Modifier 59 (Distinct Procedural Service): Use it to bypass NCCI edits when you bill CPT 28298 with a separately identifiable procedure in the same session. That procedure must be at a different anatomical site. Don’t use 59 to unbundle sesamoidectomy from 28298.
• Modifier 51 (Multiple Procedures): Some payers want it on 28298 when you bill it with another separately reportable procedure in the same session. An example is 28285 on a lesser toe. Don’t use it to pair 28298 with 28296 on the same great toe, because coders report that combination as 28299 instead.

Medicare reimbursement and fee schedule for CPT 28298 (2026)

The CMS Physician Fee Schedule (MPFS) sets Medicare reimbursement for CPT code 28298. It varies by geographic practice cost index (GPCI), facility vs. non-facility setting, and annual relative value unit (RVU) updates. Three RVU components build the allowed amount: work, practice expense, and malpractice.

Track 28298 collections against the expected allowed amount for your locality and setting. The non-facility rate usually runs higher than the facility rate, because the practice carries the overhead of an office setting.

Don’t treat payerprice.com or other third-party fee databases as authoritative 2026 rates. CMS updates the MPFS file each January. Pull the current year’s file from CMS before quoting expected reimbursement to patients or contracting with ambulatory surgery centers (ASCs).

Prior authorization requirements for bunionectomy billing

Prior authorization rules for CPT code 28298 vary by payer type, and no single rule covers them all. A claim submitted without a required authorization is a preventable write-off. Make the authorization check a standard step before scheduling surgery.

• Traditional Medicare (Parts A and B): Doesn’t require prior authorization for 28298. The practice still needs to document medical necessity thoroughly. Medicare contractors run post-payment medical record reviews (e.g., under the Recovery Audit Program) on foot surgery claims.
• Medicare Advantage plans: Frequently require prior authorization. Each MA plan sets its own criteria. Many require imaging (weight-bearing X-rays) and documented conservative treatment failure spanning at least three months.
• Commercial insurers: Most major commercial payers require prior authorization for elective hallux valgus correction. Criteria typically include radiographic evidence of deformity, a minimum intermetatarsal angle (often 13 degrees or greater), and failed conservative management.
• Medicaid: Most states require prior authorization. Medicaid criteria are often stricter than commercial criteria, and some state plans limit coverage to cases with severe functional impairment.

Document conservative treatment in the chart for at least three to six months before the surgical date. Notes should list the specific interventions tried (custom orthotics, wider footwear, padding, corticosteroid injection, physical therapy) and the patient’s response to each.

NCCI bundling edits and unbundling rules for CPT 28298

NCCI edits govern which codes coders can and can’t bill together with CPT code 28298. CMS updates the edit tables regularly, so check the current tables and the CMS NCCI Policy Manual rather than prior-year guidance.

When coders bill 28298 alongside 28285, the operative report has to show that the hammertoe correction was on a different toe from the hallux. Both procedures also need their own documented medical necessity.

Common claim denial reasons for CPT 28298

Practices that track medical billing denial codes for 28298 see the same triggers come up again and again. As a result, fixing the root cause of each denial type cuts rework and protects reimbursement.

• Wrong code selected (28296 submitted instead of 28298): A frequent coding error. It happens when a coder defaults to the more familiar chevron code without reading the note for the osteotomy site. Cross-reference the operative note before selecting the code.
• Missing laterality modifier: Medicare and most commercial payers return 28298 claims automatically when RT or LT is absent. This denial is correctable with a timely appeal but represents preventable rework. Set up a modifier scrub rule in the billing system.
• No prior authorization on file: MA plans and commercial payers deny 28298 when the practice didn’t obtain authorization before surgery. They also deny it when the performed procedure differs from the authorized one. Check authorizations against the operative procedure before claim submission.
• ICD-10 diagnosis-procedure mismatch: Submitting M20.12 (left foot) with modifier RT, or using M20.10 (unspecified) when the payer requires side-specific coding, triggers a mismatch denial. The ICD-10 laterality and the modifier must correspond.
• Sesamoidectomy billed separately: NCCI edits bundle sesamoidectomy into 28298. A separate sesamoidectomy line on the same claim date triggers an automatic edit denial. Remove the unbundled line and resubmit.
• Global period violation: Payers deny a post-operative visit billed during the 90-day global period without the right modifier. An unrelated evaluation and management (E/M) visit, for example, needs modifier 24. Know when the global period ends for each 28298 patient.

A structured denial management process for foot surgery codes starts with a monthly denial log, sorted by CPT code and denial reason code. As a result, most 28298 denials cluster around two or three root causes in any given practice, which makes systematic correction practical.

Global surgical package and post-operative care for 28298

CPT code 28298 carries a 90-day global surgical package. Medicare bundles the pre-operative visit the day before surgery, the intraoperative services, and routine post-operative care for the next 90 days into a single payment. Billing separately for services inside the global package is a compliance violation.

Knowing what falls inside and outside the global period prevents both under-billing and compliance exposure. A routine check of the surgical wound during the global period isn’t separately billable, no matter how you document the visit.

How Pabau supports CPT 28298 claim submission and tracking

Once the coder has confirmed the osteotomy site and assigned 28298, the claim still has to reach the payer and get paid. Many podiatric practices key it into a separate clearinghouse portal, then match remittances to billed charges by hand.

Practice management software like Pabau connects to the Claim.MD clearinghouse. With Pabau’s claims software for podiatrists, the claims your team has coded go out from the system that holds the appointment and patient record. You can follow each claim’s status and pull electronic remittance advice (ERA) back in to reconcile allowed amounts against billed charges.

Pabau doesn’t choose codes or modifiers for you, and your coder still owns that call. What changes is the follow-up. Your team has fewer logins and one place to see which 28298 claims are paid, pending, or denied.

Track every CPT 28298 claim to payment

Pabau sends the claims your team codes through the Claim.MD clearinghouse, tracks their status, and brings ERAs back for reconciliation. You spend less time switching portals and follow up on denials sooner.

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Conclusion

CPT 28298 is a narrow code, and that’s what makes it easy to get wrong. It fits one documented finding: an osteotomy of the proximal phalanx, with or without sesamoid removal. A chevron cut, a second osteotomy, or a Lapidus fusion each moves the claim to a different code.

The practical fix is a pre-submission check against the operative note. Confirm the cut site, the laterality modifier, and the matching ICD-10 code before the claim leaves the practice. That single step heads off the wrong-code, laterality, and mismatch denials covered above.

Book a demo to see how Pabau keeps your coded foot surgery claims moving from submission to reconciled payment.

Continue your research

Need to understand clearinghouse submission for surgical codes? Claim.MD clearinghouse guide explains how electronic claim routing works for CPT codes including foot surgery procedures.

Tracking post-payment denials across your surgical case mix? Medical claims clearinghouse overview covers how to reconcile ERA files against expected reimbursement for high-value surgical codes.

Want to verify insurance eligibility before scheduling 28298 cases? Insurance eligibility verification guide walks through the checks that confirm coverage and authorization needs before surgery day.

Seeing the same 28298 denials every month? Denial management in healthcare sets out how to log, sort, and fix denials by root cause.

Want 28298 claims paid on first submission? What is a clean claim explains what payers need to see before they process a claim without rework.

Frequently asked questions