Fusion · Hand

Surgical fusion of the thumb carpometacarpal (CMC) joint, with or without internal fixation hardware.

Verified May 8, 2026 · 6 sources ↓

Medicare: $751.19
Total RVUs: 22.49
Global, days: 90
Region: Hand

Drawn from CMSAAPCFindacodeAbosEmedny

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 6 cited references ↓

Diagnosis confirming end-stage CMC arthritis or instability with failed conservative management
Operative note specifying whether internal fixation was used and the type of hardware (K-wires, screws, plate)
Documentation that no autograft was harvested — if graft was used, 26842 applies instead
Joint position and thumb opposition angle achieved at the time of arthrodesis
Pre-operative imaging (X-ray or CT) demonstrating joint destruction or instability
Laterality clearly stated (right vs. left thumb) in both the operative report and billing

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 26841 covers arthrodesis of the carpometacarpal joint of the thumb — the articulation between the first metacarpal and the trapezium. The surgeon resects the joint surfaces, positions the thumb in functional opposition, and stabilizes the construct with or without internal fixation (K-wires, screws, or plates). The goal is permanent pain elimination and a stable, functional thumb in patients with end-stage CMC arthritis or irreducible instability. This code covers the procedure without bone graft; if autograft harvest is performed, bill 26842 instead.

The global period is 90 days. All routine post-op visits, hardware checks, and dressing changes through day 90 are bundled — bill separately only for unrelated services (modifier 79) or unplanned return to the OR for a related complication (modifier 78). Documentation must distinguish whether internal fixation was used, since that detail supports medical necessity and closes the audit gap between 26841 and its autograft sibling 26842.

Bilateral thumb CMC fusions in a single session are uncommon but billable with modifier 50. When a significantly increased level of difficulty exists — unusual anatomy, prior failed arthroplasty, severe deformity — modifier 22 applies with a supporting operative note that quantifies the extra work. Laterality modifiers (LT/RT) are required by most payers for unilateral procedures.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	7.17
Practice expense RVU	13.91
Malpractice RVU	1.41
Total RVU	22.49
Medicare national rate	$751.19
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$751.19
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI A2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 26841 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Missing laterality modifier — most payers require LT or RT on unilateral thumb procedures
Upcoded to 26842 without documentation confirming autograft harvest and donor site
Modifier 22 submitted without a separate operative note narrative quantifying increased complexity
Post-op visit billed within the 90-day global period without modifier 24 or 79 to distinguish unrelated service
Medical necessity denied when conservative therapy (splinting, corticosteroid injection) not documented prior to surgery

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01What is the difference between 26841 and 26842?

26841 is thumb CMC arthrodesis without bone graft. 26842 is the same procedure with autograft harvest included. If you used allograft only, 26841 is still the correct base code — allograft does not trigger 26842, though a separate graft code may apply.

02Does the 90-day global period bundle hardware removal?

Routine hardware removal (e.g., K-wire pull) within 90 days is bundled under the global. Unplanned return to the OR for a complication related to the arthrodesis bills with modifier 78. Hardware removal for a reason unrelated to the fusion bills with modifier 79.

03Can I bill modifier 50 if both thumbs are fused in the same session?

Yes. Bilateral same-session CMC fusions bill with modifier 50 on a single line. Reimbursement is typically capped at 150% of the single-procedure rate. Confirm bilateral medical necessity is documented for each thumb independently.

04When is modifier 22 justified for 26841?

When the procedure required substantially more work than a standard thumb CMC fusion — for example, prior failed arthroplasty with implant removal, severe deformity, or extensive scarring. The operative note must describe the specific factors that increased complexity and time; a generic mention is insufficient for most payers.

05Is 26841 performed in an ASC or hospital outpatient setting?

Both are common. HOPD and ASC payments differ significantly — see the Site of Service comparison on this page. Surgeon professional fee RVUs are the same regardless of site, but facility payment to the site varies.

06Does allograft use require a different CPT code?

No. 26842 is specifically for autograft harvest performed by the same surgeon. If you used allograft, bill 26841 as the primary code. A separate graft product code may be reportable by the facility, but that does not change the surgeon's procedure code.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira's AI scribe captures the joint fused (CMC, first metacarpal–trapezium), fixation method (K-wire, screw, or no hardware), thumb position achieved, laterality, and explicit confirmation that no bone graft was harvested. That last detail is what separates a clean 26841 claim from an unintentional 26842 — and from an audit flag when a graft site isn't documented.

See how Mira captures CPT 26841 documentation