CPT code 28755 – Arthrodesis of the great toe IP joint

Key takeaways

CPT Code 28755 reports arthrodesis of the great toe interphalangeal joint, which sits between the two phalanges, not the MTP joint fused under 28750.

Pair it with M19.071 for the right foot or M19.072 for the left, matching the operative side, rather than a hallux rigidus code.

Bilateral fusion under modifier 50 pays 150% of the unilateral rate, and many MACs prefer separate RT and LT line items instead.

The 2026 Physician Fee Schedule assigns 28755 a total of 13.99 facility RVUs and a 90-day global period.

Pabau, the practice management platform we build, tracks 28755 claims from submission through ERA posting and denial follow-up.

CPT Code 28755: Quick reference

CPT Code 28755 reports a surgical fusion of the great toe interphalangeal joint. Coders also bill it with an osteoarthritis diagnosis, an RT or LT modifier and a 90-day global period. The table below lists the fields coders check before they submit a claim. Also, verify RVU values against the current-year CMS Physician Fee Schedule, because it updates each January.

What does CPT Code 28755 cover?

CPT Code 28755 covers arthrodesis of the interphalangeal joint of the great toe, the joint between the proximal and distal phalanges of the hallux. The procedure permanently fuses the two bones, so painful motion stops at a joint damaged by osteoarthritis, post-traumatic arthritis or inflammatory arthritis.

The American Medical Association (AMA), which maintains the CPT code set, publishes the descriptor as “Arthrodesis, great toe; interphalangeal joint.” The descriptor covers the whole surgical episode, from joint prep through internal fixation. For example, the code includes these steps:

• Incision and exposure of the IP joint of the hallux
• Removal of remaining articular cartilage and subchondral bone prep to create congruent fusion surfaces
• Bone apposition and alignment in the optimal functional position (often slight plantar flexion and neutral rotation)
• Internal fixation using screws, Kirschner wires (K-wires), or a plate and screw construct
• Wound closure and dressing application

However, bone grafting is not separately billable when it is minor and part of the fusion prep. If the surgeon harvests and places a large graft, describe that work clearly in the operative report. Then check whether payer policy allows a separate graft code.

Clinical indications: When is CPT 28755 appropriate?

CPT 28755 fits when a patient has end-stage arthritis of the great toe IP joint that has not responded to recorded conservative treatment. Osteoarthritis is the usual cause, although post-traumatic and inflammatory arthritis also lead to this fusion.

Medicare Administrative Contractors (MACs) often want proof that conservative care failed before they pay for arthrodesis. However, the minimum length and the treatments required vary by MAC Local Coverage Determination (LCD), so check the LCD for your area.

First, the chart should show the conservative treatment tried before surgery:

• Orthotic devices or shoe modifications with a recorded trial period
• Anti-inflammatory medication (NSAIDs or corticosteroid injections) with response recorded
• Physical therapy or activity modification with outcomes recorded
• Radiographic proof of advanced joint-space narrowing, osteophytes, or bone-on-bone articulation at the IP joint

For this reason, the clinical record should separate IP joint problems from metatarsophalangeal (MTP) joint problems. Payers audit this difference because it decides the code. In other words, the choice is 28755, the neighboring great toe MTP fusion code 28750, or a midfoot fusion code such as 28730.

ICD-10 diagnosis codes to pair with CPT Code 28755

Hallux rigidus codes (M20.2-) describe arthritis of the first MTP joint, so they do not fit an IP fusion. Instead, primary osteoarthritis of the great toe IP joint is coded M19.07-, primary osteoarthritis of the ankle and foot. In contrast, post-traumatic or inflammatory arthritis has its own code family, so code the cause the record shows. Also, side is required, and the code must match the operative side.

First, confirm that the ICD-10 code you chose appears on your MAC LCD’s list of covered diagnoses for foot arthrodesis. For example, using M19.079 on a claim when the operative report states the side is an avoidable error. As a result, it triggers edit flags and manual review.

How CPT 28755 is performed and documented

First, payers check 28755 by comparing the operative report with the code descriptor. Therefore, each surgical step needs a note, because examiners look for proof that the joint was fused rather than reshaped by a lesser procedure.

Specifically, five operative elements must appear in the notes:

1. Approach: Describe the incision site and approach to the IP joint of the great toe, since a dorsal or medial approach is most common.
2. Joint prep: State that articular cartilage was removed from both the proximal and distal surfaces and that subchondral bone was prepared to bleeding bone.
3. Alignment: Document the position the joint was held in when it was fused (degrees of plantar flexion, neutral valgus/varus).
4. Fixation method: Name the exact hardware used: screw type and size, K-wire gauge, or plate designation. In this way, the note separates arthrodesis from arthroplasty.
5. Closure and dressing: Record layered closure and post-operative dressing applied.

For example, an operative note that says only “joint fusion of the great toe” will not survive a payer audit. Instead, it has to name the joint, the fixation method and the bone prep. That wording fits both IP joint and MTP joint procedures, which bill at other codes and other rates. As a result, a vague note invites a denial.

CPT 28755 vs related codes: How to choose the right code

In fact, the most common coding error for great toe arthrodesis is billing the MTP fusion code for an IP fusion, or the reverse. The anatomy decides the code, so start from the joint the operative note names, as the map below shows.

The AAPC Codify CPT lookup can confirm the descriptor for each of these neighboring codes before filing. Above all, the operative report must name the joint fused, not just “the great toe.”

Modifiers for CPT Code 28755

Modifier choice for 28755 depends on the side, whether the surgery was bilateral, and the clinical situation. If RT or LT is missing, a unilateral claim gives the payer no side to match against the diagnosis. As a result, some payers flag it for review.

In fact, many MACs prefer RT/LT over modifier 50 for paired bilateral claims submitted as separate line items. Therefore, check the MAC’s billing guidelines before you default to modifier 50 on a bilateral case.

Pre-authorization requirements for CPT 28755

Because prior authorization rules for 28755 vary by payer and change often, the guidance below reflects broad payer patterns. So check with each payer before scheduling surgery. Also, understanding medical billing fundamentals helps practices build a steady pre-auth workflow that reduces last-minute denials.

• Medicare: Traditional Medicare does not require prior authorization for most elective foot surgeries, including 28755. Medicare Advantage plans, however, often require prior auth, so verify with the plan.
• Medicaid: Plan ahead, because state Medicaid programs nearly always require prior authorization for elective surgery. Still, rules vary by state.
• Commercial insurers: Most commercial plans require prior auth for arthrodesis, so submit clinical notes showing failed conservative treatment, current X-ray proof, and the surgeon’s operative plan.

In addition, a prior auth request for 28755 should include four documents:

• Office visit notes documenting symptom duration and severity
• Records of the conservative treatments tried and failed
• Weight-bearing radiographs showing IP joint destruction, since the images support medical necessity
• The surgeon’s letter of medical necessity

Turnaround often runs 3 to 10 business days for non-urgent surgical requests, though payer timelines vary.

Medicare reimbursement rates for CPT Code 28755

Medicare pays for CPT Code 28755 through the CMS Physician Fee Schedule (MPFS), updated each January 1. Next, the national figures below are the 2026 MPFS relative value units (RVUs) for 28755. However, payment in a given area depends on the geographic practice cost index (GPCI) for the practice’s locality.

Then use the FastRVU lookup tool to calculate the exact current-year Medicare payment for 28755 in your locality. First, each RVU component is multiplied by its locality GPCI. Then the sum is multiplied by the annual conversion factor, which CMS publishes each November for the following year.

Common denial reasons for CPT 28755 and how to prevent them

In fact, 28755 claims fail for a small set of repeatable reasons. Therefore, a denial management workflow should catch each of them before filing. Also, each denial type below maps to a clear prevention action.

Next, use the denial codes in medical billing guide to match CARC and RARC reason codes on an EOB to the denial types above. A medical claims clearinghouse returns those codes with the ERA, so billers can act on a rejection without logging into each payer portal.

Documentation checklist for a clean CPT 28755 claim

Finally, this checklist combines the record rules across pre-operative, intraoperative and post-operative notes. Post-operative notes are on it because payers audit them as closely as the operative report. Therefore, use it when you prepare a 28755 claim or answer a records request after a denial.

Pre-operative documentation

• Office visit notes confirming IP joint pain, duration, and functional limitation
• Conservative treatment records with dates, treatment types, and patient response
• Weight-bearing radiographs with radiology report confirming IP joint-space narrowing or bone-on-bone articulation
• Surgeon’s letter of medical necessity referencing the relevant MAC LCD
• Prior authorization number (if required by payer), recorded in box 23 of CMS-1500

Operative report requirements

• Patient identification, date, surgeon name, and site of service
• Procedure name clearly stating “arthrodesis, great toe; interphalangeal joint” (not just “great toe fusion”)
• Side confirmed in the body of the note (right or left), matching the preoperative diagnosis
• Description of joint prep: cartilage removal and subchondral bone prep to bleeding bone
• Alignment position recorded in degrees, because payers expect a number
• Fixation hardware named specifically: screw type/size, K-wire gauge, or plate/screw construct
• Any same-day procedures listed separately with their own descriptions

Post-operative and claim form requirements

• Post-op note documenting the patient’s status at the first follow-up visit
• CMS-1500 box 24D: CPT 28755 with the matching modifier (RT or LT, or 50 for bilateral)
• CMS-1500 box 21: M19.071 or M19.072 (matching operative side), not M19.079
• CMS-1500 box 24B: place of service code (21 for inpatient, 22 for outpatient hospital, 24 for ASC)
• Global period tracking: no separately billable post-op visits within the 90-day global window without modifier 24 (unrelated E&M) or modifier 79 (unrelated procedure)

A checklist like this is what submitting a clean claim looks like for a code with heavy paperwork. Revenue cycle management for surgical foot practices gains most when the checklist runs at claim prep, before the claim leaves the practice.

How claims management software keeps 28755 claims clean

The denial reasons above all start when the claim is built. For example, a hallux rigidus code lands on an IP fusion, the RT or LT modifier is dropped, or the auth number never reaches box 23. As a result, billers often find out weeks later, when the remittance arrives.

Instead of chasing these errors by hand, Pabau, the practice management platform we build, runs end-to-end claims management for surgical practices. It also submits 28755 claims electronically through Claim.MD and tracks each one from filing to payment. ERA responses post against the claim automatically, so a denial reason reaches your biller the day it arrives.

Your coders still choose the CPT and ICD-10 codes. Pabau keeps the claim, the remittance and the follow-up on one record, so a rejected fusion claim gets corrected and resubmitted quickly.

Stop chasing denied 28755 claims

Pabau connects directly to Claim.MD’s clearinghouse to submit surgical foot claims, track ERA responses, and flag denials the same day they hit. See how it works for podiatry and orthopedic foot practices.

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Conclusion

Overall, the code itself is rarely the problem on a great toe IP fusion. A 28755 claim fails when the paperwork describes another joint or another diagnosis than the code does.

Before the next claim goes out, check that the operative note, ICD-10 code and modifier describe the same joint on the same side. Once that match is routine, the remaining denial reasons become exceptions rather than a pattern.

Next, book a demo to see how Pabau tracks surgical foot claims from filing to payment.

Continue your research

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Seeing ERA remittance codes you don’t recognize? Electronic remittance advice explained breaks down CARC and RARC denial codes from payer EOBs.

Want to benchmark your denial rate? Denial management in healthcare covers root-cause analysis and appeals workflow for surgical claims.

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