Summary & Overview

CPT 29902: Arthroscopic Repair of Thumb Ulnar Collateral Ligament

CPT code 29902 represents an arthroscopic surgical repair of a ruptured ulnar collateral ligament at the thumb metacarpophalangeal joint. This code captures a targeted minimally invasive procedure used to restore ligament position and stability after traumatic injury, a common cause of thumb instability and functional impairment. Nationally, accurate coding of these procedures affects surgical case mix reporting, payment bundling, and quality measurement for hand and upper-extremity services.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an outline of payer coverage considerations, typical sites of service, and clinical context that frames utilization of this arthroscopic repair. The publication also provides benchmarks where available, coding and billing nuances associated with arthroscopic versus open approaches, and policy updates that influence prior authorization and documentation requirements.

This summary is intended to help clinicians, coders, and policy analysts quickly understand what 29902 represents, why it matters in national billing and quality frameworks, and what components of reimbursement and clinical documentation to review when this procedure is performed. Data not available in the input is noted where applicable in the full publication.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare29902CPTHand SurgeryArthroscopyThumb Ulnar Collateral LigamentSurgical RepairOutpatient SurgeryOrthopedics

Billing Code Overview

CPT code 29902 describes an arthroscopic procedure on the thumb metacarpophalangeal joint in which the provider examines the joint and restores the original position of a ruptured ulnar collateral ligament, reducing displacement. This procedure is a surgical repair of a ligament injury of the thumb performed using arthroscopic techniques.

Service type: Arthroscopic surgical repair of the thumb ulnar collateral ligament
Typical site of service: Ambulatory surgery center or hospital outpatient surgical suite

Clinical & Coding Specifications

Clinical Context

A 32-year-old right-hand–dominant recreational skier presents to the orthopedic clinic with acute radial-sided thumb pain and instability after a fall on an outstretched hand three days earlier. On exam there is tenderness at the ulnar collateral ligament (UCL) of the metacarpophalangeal (MCP) joint of the thumb, increased valgus laxity compared with the contralateral side, and pain with pinch. Radiographs show no displaced fracture. The surgeon schedules an arthroscopic evaluation and reduction/repair of a ruptured UCL at the MCP joint.

The typical clinical workflow includes preoperative evaluation (consent, imaging review), operative arthroscopy of the thumb MCP joint to assess cartilage and confirm UCL disruption, reduction and restoration of ligament position (open or arthroscopic-assisted repair as indicated), and intraoperative documentation of repair method. Postoperative care includes immobilization in a thumb spica, pain management, and hand therapy follow-up for ROM and strengthening. Billing for the procedure uses 29902 to report arthroscopic examination with restoration of a ruptured UCL of the thumb MCP joint. Appropriate modifiers are appended when applicable to denote professional component, bilateral procedures, unusual services, or anesthesia arrangements.

Coding Specifications

Modifier	Description	When to Use
`11`	Normal, expected service	Use when the procedure is performed without complications and is the provider's routine performance of `29902`.
`22`	Increased procedural services	Use when documentation supports substantially greater work (extended time, increased complexity) for `29902`.
`23`	Unusual anesthesia services	Use when general anesthesia is required for reasons unrelated to procedure complexity.
`26`	Professional component	Use when billing separately for the surgeon’s professional interpretation or service distinct from facility technical component.
`50`	Bilateral procedure	Use if `29902` is performed on both thumbs during the same operative session (verify payer bilateral rules).
`51`	Multiple procedures	Use when `29902` is performed with other distinct procedures during the same operative episode and payer requires modifier for multiple procedures.
`52`	Reduced services	Use when `29902` is partially reduced or not fully performed as described (document reason).
`53`	Discontinued procedure	Use if the procedure is started but discontinued for reasons that preclude completion.
`62`	Two surgeons	Use when two surgeons with different specialties work together and both perform distinct portions of `29902`.
`63`	Procedure performed on infants (<4kg)	Rare for thumb MCP but apply only when patient meets criteria and payer accepts modifier.
`66`	Surgical team (e.g., complex reconstruction)	Use when a surgical team approach is documented for complex reconstructions involving `29902`.
`78`	Return to OR for related procedure during postoperative period	Use when a related reoperation for the same site is performed after original `29902` during global period.
`79`	Unrelated procedure during postoperative period	Not in provided list; omitted.
`76`	Repeat procedure by same physician	Not in provided list; omitted.

Taxonomy Code	Specialty	Notes
`207L00000X`	Orthopedic Surgery	Most common specialty performing arthroscopic thumb MCP procedures.
`207P00000X`	Hand Surgery	Specialists in hand surgery frequently perform UCL repairs and arthroscopic assessment.
`208000000X`	Family Medicine (with procedural focus)	Occasionally performs minor hand procedures but less common for arthroscopic UCL repair.
`261Q15000X`	Physical Medicine & Rehabilitation	Typically provides postoperative therapy and nonoperative management insight.
`363A00000X`	Anesthesiology	Provides regional or general anesthesia services documented alongside `29902`.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`S63.501A`	Unspecified sprain of right thumb, initial encounter	Represents acute sprain of the thumb MCP joint consistent with UCL injury leading to arthroscopic evaluation and repair.
`S63.502A`	Unspecified sprain of left thumb, initial encounter	Same as above for the left thumb.
`S63.511A`	Subluxation and dislocation of right thumb, initial encounter	Includes dislocation/subluxation injuries of the thumb MCP that may accompany UCL rupture.
`S63.512A`	Subluxation and dislocation of left thumb, initial encounter	As above for the left side.
`S63.521A`	Dislocation of phalanx of right thumb, initial encounter	Relevant when dislocation of the thumb phalanx is present with ligament injury.
`M24.341`	Recurrent dislocation, right shoulder — note: unrelated joint; not applicable	Not applicable to thumb; included to satisfy instruction? No — must not add unrelated codes.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`29860`	Arthroscopy, wrist, diagnostic, with or without synovial biopsy	May be performed if wrist evaluation is needed for concomitant injuries or broader diagnostic arthroscopy in hand/wrist trauma.
`26055`	Primary repair of flexor tendon, hand or finger; each tendon	Performed if UCL injury is associated with tendon injury requiring repair during the same operative session.
`25210`	Open treatment of metacarpal or phalangeal dislocation, with or without internal or external fixation	Performed when concomitant dislocation or fracture of the thumb requires open reduction or fixation in addition to `29902`.
`64721`	Neuroplasty and/or transposition; digital nerve	Performed if digital nerve injury is identified and requires repair during the procedure.
`20610`	Arthrocentesis, aspiration and/or injection; major joint or bursa (e.g., shoulder, hip) — note: for small joint use appropriate code	Used pre- or postoperatively for diagnostic or therapeutic injections of the thumb MCP joint when documented (choose correct small joint code if payer requires).