CPT code 28750: Arthrodesis, great toe metatarsophalangeal joint

CPT code 28750 is the procedure code for arthrodesis of the great toe at the metatarsophalangeal (MTP) joint, covering surgical fusion of the first MTP joint to correct conditions such as hallux rigidus and severe hallux valgus. Podiatric and orthopedic practices billing this code face a specific set of documentation and modifier decisions that directly affect reimbursement.

According to the American Medical Association (AMA), CPT codes must be reported with precision to reflect the actual procedure performed. This guide covers the official descriptor, clinical indications, ICD-10 crosswalk, applicable modifiers, 2026 Medicare fee schedule data, RVU values, documentation requirements, and related codes for CPT billing workflows in foot surgery practices.

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Key Takeaways

CPT code 28750 describes surgical fusion of the great toe MTP joint, distinct from interphalangeal joint fusion (CPT 28760).

Primary ICD-10 indications are hallux rigidus (M20.20-M20.22) and hallux valgus (M20.10-M20.12); bilateral variants require the appropriate laterality codes.

Modifier 50 covers bilateral procedures, but some payers require separate line billing with LT/RT instead; verify individual payer policy before submitting.

Pabau’s claims management software supports coding accuracy and clean claim submission for foot and ankle surgery practices.

What is CPT code 28750?

CPT code 28750 is the billing code for arthrodesis of the great toe at the metatarsophalangeal joint, as defined in the AMA’s Current Procedural Terminology. The official descriptor reads: Arthrodesis, great toe; metatarsophalangeal joint. This is a Category I CPT code that falls within the musculoskeletal surgery section covering foot and ankle procedures.

The procedure involves surgically fusing the first metatarsal head to the proximal phalanx of the great toe, eliminating motion at that joint. Surgeons typically use internal fixation hardware (plates, screws, or crossed screws) to hold the bones in the corrected position while fusion occurs. CPT 28750 captures only the MTP joint fusion; interphalangeal joint fusion is reported separately under CPT 28760.

Clinical indications for CPT 28750

First MTP joint arthrodesis is indicated when conservative treatment fails to relieve pain or correct deformity. Payers expect documentation showing that non-surgical options (orthotics, corticosteroid injections, physical therapy, shoe modification) were tried and did not produce adequate relief before surgery was considered.

The two primary diagnoses driving billing for CPT 28750 are hallux rigidus and severe hallux valgus. Hallux rigidus involves progressive cartilage loss and osteophyte formation at the MTP joint that restricts dorsiflexion; end-stage cases cause significant functional impairment. Severe hallux valgus with a high intermetatarsal angle that is not amenable to osteotomy correction is another common indication, particularly in revision cases.

• Hallux rigidus (end-stage): Grade III or Grade IV, with joint space obliteration on imaging
• Severe hallux valgus: Intermetatarsal angle too large for osteotomy or failed prior correction
• Hallux valgus with arthritis: MTP joint degeneration alongside angular deformity
• Rheumatoid arthritis affecting the MTP joint: With joint destruction and progressive deformity
• Failed prior MTP surgery: Revision arthrodesis following failed bunionectomy or previous implant
• Traumatic arthritis: Post-fracture joint destruction at the first MTP level

ICD-10 codes commonly paired with CPT 28750

These ICD-10-CM codes are commonly documented alongside CPT 28750 to establish medical necessity. Payers match the diagnosis code to the procedure; an imprecise or non-specific code is a common reason for denial. Use laterality-specific codes (right, left, bilateral) wherever the clinical record supports them, and refer to ICD-10-CM diagnosis coding best practices for proper specificity selection.

Modifiers for CPT code 28750

Modifier selection for CPT 28750 depends on the operative site (right, left, or bilateral) and any circumstances affecting complexity. Incorrect modifier use is one of the top causes of claim rejection for foot surgery codes. Confirm modifier policies with each payer’s local coverage determination (LCD) before submitting, as rules on bilateral reporting in particular vary.

2026 Medicare fee schedule for CPT 28750

Medicare reimbursement for CPT 28750 varies by geographic location, and the figures below represent national averages based on the 2026 Medicare Physician Fee Schedule. Use the CMS Physician Fee Schedule Look-Up Tool to obtain your practice’s specific locality-adjusted rates, as the geographic practice cost index (GPCI) affects all three RVU components. Rates are also different in facility settings (hospital outpatient department or ASC) versus non-facility (office) settings.

Important: The figures above are estimates based on publicly available fee schedule data and should be verified against the official CMS MPFS for your geographic locality and the applicable year. Private payer rates vary substantially and may be higher or lower than Medicare. Submitting claims through electronic claims via Claim.MD allows practices to route 28750 claims to over 4,000 US payers with built-in CPT code validation, reducing the risk of errors on high-value surgical claims. After submission, electronic remittance advice (ERA/835) documents exactly what the payer paid and why, making reconciliation straightforward.

RVU breakdown for CPT 28750

Relative value units (RVUs) quantify the physician work, practice expense, and malpractice components that together determine Medicare payment. For CPT 28750, the 2026 RVU values reflect a moderately complex surgical procedure with a standard global surgery period of 90 days. The work RVU captures surgeon time and cognitive effort; the practice expense RVU differs between facility and non-facility settings because overhead costs differ.

RVU figures are approximate and should be confirmed using the CMS Physician Fee Schedule or the medical claims clearinghouse tools your practice uses for pre-submission validation. The 90-day global period means routine follow-up visits within 90 days of surgery are bundled into the 28750 payment; billing an evaluation and management code during that window requires a modifier 24 to indicate the visit is unrelated to the surgical condition.

Documentation requirements for CPT 28750

Thorough documentation is the front line against claim denial and audit exposure. Payers reviewing claims for first MTP joint arthrodesis look for evidence of medical necessity and operative specificity. The operative report must describe the actual procedure performed at that joint, not a generic fusion template. Drawing on medical necessity documentation principles that apply across surgical codes, the record for 28750 should contain all of the following elements.

• Conservative treatment history: Documentation showing orthotics, injections, physical therapy, or shoe modification were attempted and failed
• Pre-operative imaging: Weight-bearing X-rays confirming joint space loss, osteophyte formation, or angular deformity
• Operative report specifics: Patient positioning, approach used (dorsal, medial), type of fixation (plate, screws, crossed K-wires), bone preparation technique, and the joint level fused
• Intraoperative findings: Description of cartilage status, osteophyte size, and any bone grafting performed
• Position of fusion: Stated degrees of hallux dorsiflexion and valgus angle at time of fixation
• Diagnosis linkage: The operative report diagnosis must align with the ICD-10-CM code reported on the claim
• Laterality: Clearly documented right, left, or bilateral

Some payers require prior authorization for elective foot arthrodesis. Confirm authorization requirements before scheduling the procedure, as retro-authorization is not always granted. General documentation guidance applies; always consult the individual payer’s LCD for CPT 28750 to confirm their specific requirements.

Billing guidelines and common coding errors for CPT 28750

Understanding medical billing fundamentals matters for foot surgery coding, where bundling rules and bilateral billing create predictable error patterns. The following issues are the most common sources of claim denial on CPT 28750 submissions.

• Billing 28750 and 28760 together without a modifier: MTP joint fusion (28750) and interphalangeal joint fusion (28760) can be performed simultaneously, but most payers apply bundling edits. Report both with modifier 59 on the lesser procedure to indicate distinct procedural services, and ensure the operative report documents both joint levels.
• Missing bilateral modifier: When both feet are operated on, the claim must include modifier 50 (or separate LT/RT lines, depending on the payer). Submitting 28750 on a single line without a bilateral indicator typically results in payment for one side only.
• Non-specific ICD-10 code: Submitting M20.10 (unspecified foot) when the record documents left or right foot is a missed opportunity for specificity and may trigger medical review at some payers.
• Unbundling incidental procedures: Bone grafting performed as part of the fusion is typically included in 28750; billing a separate bone graft code may trigger an NCCI edit rejection.
• E/M visits during the global period: Follow-up visits in the 90-day global window require modifier 24 (unrelated) or modifier 79 (unrelated procedure) if a new procedure is performed; routine post-op care is not separately billable.

Tracking denial codes in medical billing after 28750 submissions reveals which error patterns recur in your practice. CO-4 (procedure code inconsistent with modifier), CO-97 (payment included in another service), and CO-57 (prior authorization required) are the denial codes most commonly reported for foot arthrodesis claims. Clean claim submission starts with complete documentation; the clean claim standard means a claim that passes all edits on first submission without requiring manual intervention.

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Pabau’s claims management tools help podiatric and orthopedic practices submit accurate claims for complex surgical codes like CPT 28750, track denials by code, and reconcile ERA payments automatically.

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CPT 28750 vs CPT 28760: key differences

CPT 28750 and CPT 28760 are two distinct arthrodesis codes for the great toe, differing by which joint is fused. Selecting the wrong code is a coding error, not just a technical mismatch; auditors specifically look for operative report language that confirms the joint level.

Related CPT codes for great toe and foot arthrodesis

CPT 28750 sits within a family of foot and ankle codes used to capture related procedures. When multiple procedures are performed at the same operative session, each must be reported separately with appropriate modifiers. The table below shows the codes most frequently referenced alongside 28750, including related foot arthrodesis codes and hallux correction procedures. For general reference on surgical procedure billing codes, multiple codes in the same session require payer-specific review of NCCI edits.

How practice management software supports CPT 28750 billing

Podiatric and orthopedic practices billing high-value surgical codes like CPT 28750 benefit from claims management software that validates code combinations, modifier logic, and diagnosis linkage before claims leave the practice. Manual coding review for each surgical encounter is time-consuming and error-prone, particularly when multiple codes are reported in the same session.

Pabau integrates with Claim.MD, a US medical claims clearinghouse connected to over 4,000 payers. For physical therapy and orthopedic practice management, this means CPT 28750 claims route electronically, real-time eligibility checks confirm patient coverage before surgery, and ERA remittances post automatically after payment. Practices can see exactly which claims for foot arthrodesis were paid, adjusted, or denied, and drill into denial codes without switching between systems.

Conclusion

CPT code 28750 requires precise modifier selection, laterality-specific ICD-10 coding, and operative documentation that clearly identifies the MTP joint as the site of fusion. Getting any one of those elements wrong translates directly into denials or audit exposure on a surgical claim worth several hundred dollars.

Pabau’s claims management software, integrated with the Claim.MD clearinghouse, helps podiatric and orthopedic practices submit 28750 claims accurately, track ERA responses by code, and resolve denials before they age. To see how Pabau supports surgical billing workflows, book a demo with the team.

Continue your research

Want to understand how clearinghouse claims routing works? Medical claims clearinghouse guide explains how electronic claims move from practice to payer and where errors get caught.

Need to track denial patterns across surgical codes? Denial management in healthcare covers how to categorise, appeal, and reduce claim denials systematically.

Looking for guidance on ERA remittance reconciliation? Medical superbill guide walks through how superbills connect to clearinghouse submissions and ERA matching.

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