Fusion · Hand

Arthrodesis of the metacarpophalangeal joint using an autograft harvested during the same operative session, with or without internal fixation.

Verified May 8, 2026 · 7 sources ↓

Medicare: $795.28
Total RVUs: 23.81
Global, days: 90
Region: Hand

Drawn from CMSMdclarityAAPCNIHFastrvu

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify the exact digit(s) and MCP joint level treated (e.g., index, long, ring, small finger)
Document the diagnosis driving fusion — arthritis type, instability, prior failed surgery, or trauma
Record the autograft harvest site and confirm it is ipsilateral or contralateral as appropriate
State the fusion position (degrees of flexion) and fixation method used (K-wire, plate, screw, or none)
Confirm medical necessity with pre-op imaging showing joint destruction or instability
Document failure of conservative management if payer requires prior authorization

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 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 26852 covers surgical fusion of the metacarpophalangeal (MCP) joint — the knuckle where the metacarpal meets the proximal phalanx — using an autograft to stimulate bone union. The autograft harvest is included in the code; don't bill a separate graft-harvest code (e.g., 20900–20924) alongside 26852. Internal fixation, if used, is also bundled.

Indications typically include end-stage MCP arthritis (rheumatoid, post-traumatic, or osteoarthritis), chronic instability, or failed prior MCP surgery. The operative note must specify the digit(s) treated, the position of arthrodesis, the graft source, and whether internal fixation was placed. Vague language like 'knuckle fusion performed' without joint-level specificity invites medical necessity denials.

The 90-day global period covers all routine post-op care through day 90. New or unrelated problems in that window require modifier 24 (E/M) or 79 (procedure). A staged revision or augmentation of a nonunited fusion billed in the global window requires modifier 58.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	8.49
Practice expense RVU	13.71
Malpractice RVU	1.61
Total RVU	23.81
Medicare national rate	$795.28
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	$795.28
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 26852 get rejected.

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

Separate billing of graft harvest codes (20900–20924) when harvest is included in 26852
Missing digit-level specificity in the operative note — 'MCP fusion' without naming the finger
Lack of pre-op imaging or documented conservative treatment failure to support medical necessity
Incorrect modifier when billing during the global period of a prior related hand procedure
Bilateral MCP fusions coded without modifier 50 or separate LT/RT line items per payer policy

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01Is autograft harvest billed separately with 26852?

No. Graft procurement is included in 26852 per the code descriptor. Billing 20900–20924 alongside 26852 will be bundled and denied under NCCI policy — the code explicitly covers obtaining the graft.

02How does 26852 differ from 26850?

26850 covers MCP arthrodesis without a graft. Use 26852 when an autograft is required to achieve fusion — typically in revision cases, post-traumatic defects, or when bone stock is insufficient for primary fusion alone.

03Can you bill 26852 for multiple fingers in the same session?

Yes. Bill a separate unit of 26852 for each MCP joint fused. Apply modifier 51 on the secondary procedures and use RT/LT or specific digit modifiers as required by the payer to distinguish each joint.

04What modifier applies if the surgeon returns to the OR during the 90-day global to address a nonunion?

Use modifier 58 for a planned or staged return to address the nonunion — it's a related procedure within the global. Modifier 78 applies only for an unplanned return for a complication directly related to the original surgery, such as hardware failure requiring urgent revision.

05Does the site of service affect reimbursement for 26852?

Yes. HOPD and ASC payments differ significantly from the professional fee — see the Site of Service comparison table on this page. The physician professional fee is the same regardless of setting, but facility payment to HOPD versus ASC varies.

06When is modifier 22 justified for 26852?

Modifier 22 is appropriate when the procedure required substantially more work than typical — for example, severe periarticular scarring from prior surgery, complex deformity correction, or unusually difficult graft harvest. Document the added time and complexity explicitly in the operative note; payers will request it.

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 digit name, joint level, arthrodesis position in degrees, graft harvest site, and fixation device from the surgeon's dictation — then flags if any of those elements are missing before the note is finalized. That prevents the most common audit flag on 26852: an operative note that confirms a fusion happened but omits which finger and at what position, triggering medical necessity review.

See how Mira captures CPT 26852 documentation