CPT code 28299: Double osteotomy bunionectomy billing guide

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Key takeaways

CPT 28299 covers hallux valgus correction by double osteotomy, with sesamoidectomy bundled in when the surgeon performs it.

The two cuts can fall on the same bone or on two different bones, and both belong in the operative note.

Total RVUs run 31.03 in the office and 16.87 in a facility, which pays about $1,036 and $563 in 2026.

Laterality drives denials, so LT or RT has to agree with the M20.11 or M20.12 on the diagnosis line.

A 90-day global period follows the surgery, so routine post-operative visits are already paid for.

CPT code 28299 covers correction of hallux valgus (bunionectomy), with sesamoidectomy when performed, by double osteotomy, any method.

The operative note has to show two bone cuts. Those cuts can sit on the same bone or on two different bones, as long as the surgeon documents both.

Podiatrists and orthopedic surgeons use 28299 for the most involved bunion corrections, and Medicare’s 2026 non-facility rate lands just above $1,000. Reaching for it over single-osteotomy 28296 without a note to back it up is a classic upcoding finding on audit.

What the CPT code 28299 descriptor actually covers

CPT code 28299 sits in the Surgery section of the CPT code set, under Musculoskeletal System, Foot and Toes. The American Medical Association publishes the official descriptor each year. Its exact wording decides more here than in most code families.

The full descriptor reads: Correction, hallux valgus (bunionectomy), with sesamoidectomy, when performed; with double osteotomy, any method.

Four phrases in that line carry coding weight.

Two osteotomies, not two bones, is what 28299 asks for

Count the osteotomies in the operative report and the choice between CPT 28296 and CPT code 28299 makes itself. Two cuts means 28299. One cut means 28296, whatever else the surgeon did that session.

A double osteotomy qualifies when both cuts fall inside the first metatarsal. It also qualifies when one cut sits in the metatarsal and the other in the proximal phalanx. The familiar pairing is an Austin (chevron) osteotomy with an Akin osteotomy of the phalanx. A proximal and a distal cut in the same metatarsal counts too.

The rest of the hallux valgus family divides the same way, on what the surgeon cut rather than on how hard the case was.

Billing 28299 on a single-cut note is upcoding, and auditors read operative reports. Billing 28296 on a two-cut note quietly costs the practice several hundred dollars a case. These codes also carry a medically unlikely edit of 1, so a second unit on the same line will not pay.

Sesamoidectomy is bundled, but the note still has to say so

Sesamoidectomy is conditionally included under the “when performed” language. Three rules follow from that.

• If it happens in the same session, it is bundled into 28299 and cannot be billed separately.
• If the surgeon skips it, 28299 still stands for the double osteotomy on its own.
• Either way, the report says which, and it names the sesamoid when one was excised.

Laterality modifiers do most of the work on a 28299 claim

Every 28299 claim needs LT or RT, and that one modifier causes more denials than the rest of the set combined. Three others come up often enough to plan for.

Bilateral bunionectomies are the case most often built wrong. Check the payer’s policy before you split the claim, because the modifier 50 route and the LT/RT route pay differently.

Where the 31.03 RVUs on CPT code 28299 come from

CPT 28299 carries 31.03 total RVUs in the office and 16.87 in a facility. Practice expense explains the whole difference, because an office absorbs the supplies, instruments and staff time a hospital bills for itself. The FastRVU lookup tool confirms current values by code and locality.

Watch the source you copy from. Several published tables still show a work RVU near 15 for this code, which inflates every estimate built on it. CMS revises the values each year in the Physician Fee Schedule final rule. Confirm them through the CMS Physician Fee Schedule lookup tool before you rebuild a fee schedule.

What Medicare pays for CPT code 28299 in 2026

Medicare’s 2026 national average is about $1,036 in the office and about $563 in a facility. Place of service drives that entire spread. Geography then moves it again, because the geographic practice cost index adjusts each RVU component to your locality.

The math is short enough to do by hand. Multiply total RVUs by the conversion factor, which gives 31.03 × $33.40 = $1,036.40 in the office and 16.87 × $33.40 = $563.46 in a facility. CMS set two conversion factors for 2026, $33.40 for most practices and $33.57 for qualifying APM participants.

Commercial rates usually run above Medicare on surgical codes this size, though contracts vary widely. Track the paid-to-billed ratio by payer for 28299 instead of assuming the contract holds.

The 90-day global period, and the modifiers that get you out of it

CPT 28299 carries a 090 global indicator. That covers the day before surgery, the day of surgery and the 90 days after it. Routine follow-up inside the window is already paid for, so dressing changes, wound checks and suture removal do not get billed again.

Work that falls outside the routine still gets paid, as long as a modifier says why.

• Modifier 24 covers an evaluation and management visit during the 90 days for an unrelated problem.
• Modifier 58 covers a staged or more extensive procedure that was planned at the time of the first one.
• Modifier 78 covers an unplanned return to the operating room for a related problem, such as hardware failure.
• Modifier 79 covers an unrelated procedure by the same surgeon inside the global window.

Missing one of these is a quiet revenue loss. The claim comes back denied as bundled, and denials that look like a global-period rejection rarely get reworked.

M20.1x codes carry the medical necessity

Every 28299 claim needs an ICD-10-CM diagnosis that establishes medical necessity, and for this procedure that is the M20.1x group, hallux valgus (acquired). The final digit sets the laterality.

Our ICD-10-CM codes library covers the wider set when the chart carries more than one foot diagnosis.

Three places record the side. The diagnosis line, the procedure line modifier and the operative note all have to agree. A mismatch between any two of them is one of the most common denials in foot surgery.

Six lines in the operative note that protect the claim

Denials and downcodes on 28299 nearly always trace back to the operative report rather than to the claim form. Six elements do the heavy lifting.

• The osteotomy count. Name each cut and the bone it was made in. An Austin chevron osteotomy of the first metatarsal and an Akin osteotomy of the proximal phalanx is the standard wording.
• Sesamoidectomy status. State whether it was performed. If it was, give the indication and say which sesamoid.
• Radiographic angles. Pre-operative hallux valgus and intermetatarsal angles support the decision to make two cuts instead of one.
• Technique and fixation. Record screw type, size and placement, or confirm that no internal fixation was used.
• Laterality. The words “left foot” or “right foot” have to match the diagnosis suffix and the modifier.
• Failed conservative care. Note the shoe modifications, orthotics or padding tried before surgery was offered.

Practices working from an electronic record can build these six prompts into the operative note template. The surgeon then confirms each one before signing, rather than reconstructing it weeks later for an appeal.

A 60-second check before you submit

Run the claim past this list before it leaves the practice. It catches the errors that otherwise surface on a remittance three weeks later.

• Does the note name two osteotomies, with the bone for each?
• Does LT or RT sit on the line, and does it match the M20.1x suffix?
• If both feet were done, has the payer’s bilateral rule been checked?
• Is modifier 22 backed by a separate narrative, or should it come off?
• Is there a separate sesamoidectomy code on the claim that needs deleting?
• Is the patient still inside a global period from an earlier surgery?
• Was eligibility verified for this date of service?

A clean claim rate above 95% on 28299 is achievable, and this check is most of how practices get there.

Where 28299 claims actually go wrong

Six failure points account for most denied and recouped 28299 claims.

• Upcoding from 28296. Billing 28299 on a note that documents one cut. Auditors pull the operative report, so this is fraud exposure rather than a coding slip.
• A missing laterality modifier. Leaving off LT or RT suspends the claim at most payers before anyone reviews it.
• A laterality mismatch. M20.11 paired with modifier LT trips an automated edit immediately.
• Unbundling the sesamoidectomy. A separate sesamoid code alongside 28299 for the same session gets denied, or recouped later.
• Modifier 22 with no narrative. The extra payment is recoverable on audit, and the pattern draws attention to your other claims.
• No record of conservative care. Payers increasingly want evidence that non-surgical treatment failed before they approve surgery.

Sorting denials by reason code after each remittance cycle shows which of the six is costing you. Two cycles is usually enough to see the pattern.

How 28299 fits the rest of the bunionectomy family

28299 sits at the top of a family that runs from 28292 to 28299, with a few neighbors that often appear on the same claim. Knowing the range prevents both the accidental downcode and the combination that gets bundled.

When 28299 and 28285 are performed in the same session on different sites, they can go on one claim with modifier 59 on 28285. The sites here are the first metatarsophalangeal joint and a lesser digit. Check the AAPC CPT code reference for the current edits on that pair.

How Pabau keeps 28299 claims moving from note to payment

A 28299 claim passes through five steps before it pays. Eligibility, the operative note, the coded claim, the clearinghouse and the remittance each live in a different place in most practices. The manual handoffs between them are where laterality mismatches and missing modifiers get in.

Practice management software like Pabau keeps that run inside one record. Pabau’s claims management software runs electronic eligibility checks ahead of the date of service. It then submits the claim through an integrated clearinghouse and posts the remittance back to the same patient record.

It will not pick the code for you. Pabau does not validate a CPT and ICD-10 pairing, and it does not read an operative note. The osteotomy count and the laterality check stay with your coder. What it removes is the re-keying between systems, which is where most 28299 denials start.

For a podiatry or orthopedic practice, one episode of care spans the surgery, the post-operative visits and often therapy. Holding them in a single record keeps the global period visible to whoever books the next appointment.

Keep surgical claims clean from note to payment

Pabau brings scheduling, clinical notes and claims submission into one record, so podiatry and orthopedic teams spend less time rekeying data and chasing denials.

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Conclusion

28299 is a documentation code before it is a payment code. Two osteotomies named in the note, matching laterality on both lines, and a clear sesamoidectomy statement will carry almost every claim through. The arithmetic after that takes a minute to check.

The money usually leaks after the coding decision, during the 90 days that follow. A global-period modifier gets missed, or a denial sits unworked until the filing window closes. Build both checks into the workflow once and the code stops being a problem.

Pabau links the operative note, the claim and the remittance in one patient record. A 28299 case never has to be rebuilt from three systems later. Book a demo to see how it handles surgical billing for podiatry and orthopedic practices.

Continue your research

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Need a primer on how clearinghouses process surgical claims? Medical claims clearinghouse covers the 837P transaction flow, payer enrollment, and how ERA files return to your practice.

Looking to benchmark your billing operation? Best medical billing software for US practices evaluates the leading platforms against real-world RCM criteria.

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