Summary & Overview
CPT 28310: Osteotomy of Proximal Phalanx of First Toe
CPT code 28310 represents an osteotomy of the proximal phalanx of the first toe, a common surgical corrective procedure for hallux deformities and first-toe malalignment. Nationally, this code is used in orthopedic and podiatric surgical settings to report bone-cutting procedures that realign the great toe and address symptomatic deformity. It matters because accurate coding affects clinical documentation, payment adjudication, and quality measurement across outpatient surgical sites.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for when 28310 is reported, typical sites of service, and the typical service type. The publication presents benchmarks and coding considerations used by major payers, summarizes policy and coverage updates relevant to surgical correction of hallux deformities, and highlights documentation elements commonly reviewed during claims adjudication.
This national overview is intended for coding professionals, revenue cycle staff, and clinicians who need a clear description of the procedure, payer landscape, and the types of operational and policy issues that commonly arise when billing for proximal phalanx osteotomies of the first toe.
Billing Code Overview
CPT code 28310 describes an osteotomy of the proximal phalanx of the first toe performed to correct alignment and deformity. This procedure involves surgically cutting and repositioning a portion of the bone in the proximal phalanx of the great toe to restore proper joint alignment and relieve deforming forces.
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Service type: Surgical orthopedic procedure (bony corrective surgery of the forefoot)
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Typical site of service: Ambulatory surgery center or hospital operating room for outpatient or inpatient foot surgery
Clinical & Coding Specifications
Clinical Context
A typical patient is a 55-year-old ambulatory adult presenting with progressive hallux valgus (bunion) and first-ray deformity causing medial eminence pain, shoe-gear difficulty, and transfer metatarsalgia. Conservative measures (shoe modification, orthotics, NSAIDs, corticosteroid injections) have failed. After preoperative evaluation including weight-bearing foot radiographs that confirm metatarsophalangeal alignment and proximal phalanx malalignment, the orthopedic foot and ankle or podiatric surgeon schedules a corrective osteotomy of the proximal phalanx of the first toe (CPT 28310) to realign the phalanx and improve joint mechanics. The procedure is typically performed in an ambulatory surgery center or hospital outpatient surgical suite under regional block with monitored anesthesia care or general anesthesia. Intraoperative steps include incision over the proximal phalanx, exposure, execution of the osteotomy (e.g., closing wedge, medial eminence resection if concurrent), fixation with pins, screws, or plates as indicated, and layered closure. Postoperative workflow includes recovery in PACU, short-term analgesia, weight-bearing instructions in a postoperative shoe or boot, wound checks at 10–14 days, and progressive rehabilitation with follow-up radiographs to confirm healing and alignment. Billing commonly occurs under facility or professional claims with appropriate laterality modifiers (RT/LT) and other applicable modifiers for global period adjustments or complicating circumstances.
Coding Specifications
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