Opponensplasty performed via tendon transfer with a free graft to restore thumb opposition; graft harvest is included in the code.

Verified May 8, 2026 · 7 sources ↓

Medicare: $902.49
Total RVUs: 27.02
Global, days: 90
Region: Hand

Drawn from CMSAAPCEatonhandEmednyAAOS

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify opponensplasty technique by name and confirm a free tendon graft was used (not just rerouting).
Identify the donor tendon and document graft harvest site, length, and preparation — harvest is bundled but must be described to justify code selection over 26490.
Document the motor deficit or pathology driving the procedure (e.g., median nerve palsy etiology, thenar atrophy, failed conservative management).
Name each tendon transferred when billing multiple units; generic references to 'tendon transfer' without anatomic specificity trigger audits.
Record pre-op opposition testing (Kapandji score or equivalent) to support medical necessity.
Describe the routing path and fixation method of the transferred tendon for completeness and to distinguish from other opponensplasty variants.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 26492 covers opponensplasty using a tendon transfer augmented by a free graft — the classic procedure for restoring thumb opposition when intrinsic thenar muscle function is lost, most commonly from median nerve palsy (traumatic, post-carpal tunnel, or congenital). The code explicitly includes obtaining the graft, so you cannot separately bill graft harvest codes such as 20900-20924. If the operative note describes graft procurement as a separate step, that work is still bundled — per CMS NCCI Chapter 4, any graft harvest described within the primary code's descriptor is not separately reportable.

The 90-day global period starts on the day of surgery and covers all routine post-op management, wound care, and standard follow-up through day 90. Unrelated E/M services in that window require modifier 24. A staged or planned second procedure in the global requires modifier 58; an unplanned return to the OR for a related complication uses modifier 78. Document clearly whether any same-day procedure (e.g., tenolysis, additional tendon transfer at a separate site) is distinct enough to survive NCCI scrutiny — modifier 59 or XS applies only when anatomic separation is real and documented.

Code selection within the opponensplasty family hinges on technique: 26490 is the superficialis transfer type (no free graft); 26492 requires a free tendon graft; 26494 is hypothenar muscle transfer; 26496 covers other methods. Upcoding 26490 to 26492 without documented graft harvest is an audit flag. Each tendon transferred is billable separately per the 'each tendon' descriptor language, but payer policies on multiple units vary — verify MUE limits before billing more than one unit.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	9.59
Practice expense RVU	15.38
Malpractice RVU	2.05
Total RVU	27.02
Medicare national rate	$902.49
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	$902.49
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 26492 get rejected.

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

Separate billing of graft harvest (e.g., 20900) — it is bundled into 26492 per NCCI policy and will be denied.
Code billed as 26492 when the operative note describes a superficialis transfer without a free graft — correct code is 26490.
Medical necessity not established: no documented motor deficit, nerve injury diagnosis, or failed conservative treatment on file.
Multiple units billed without per-tendon documentation or exceeding payer MUE limits without supporting notes.
Modifier missing on a same-day procedure that triggers an NCCI edit — XS or 59 required when a distinct separate tendon procedure is performed.

Frequently asked questions

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

01Can I separately bill graft harvest when performing 26492?

No. Graft procurement is explicitly included in the 26492 descriptor. Billing 20900 or similar harvest codes alongside 26492 will be denied under NCCI bundling rules.

02What distinguishes 26492 from 26490?

26490 covers the superficialis tendon transfer type without a free graft. 26492 requires an actual free tendon graft be harvested and used. The operative note must document graft harvest to support 26492; if no free graft was taken, 26490 is correct.

03If I transfer two tendons during the same session, can I bill 26492 twice?

The 'each tendon' language supports multiple units, but each transfer must be separately documented by tendon name and anatomic site. Check the payer's MUE value and expect to append modifier 51 or 59 with supporting documentation.

04What modifier applies if I return to the OR during the 90-day global for a related complication?

Modifier 78 — unplanned return to the OR for a procedure related to the original surgery. Modifier 79 is for an unrelated procedure in the global period. Don't invert them.

05Is 26492 typically performed in an ASC or hospital outpatient setting, and does it affect payment?

It is performed in both settings. Site of service affects the facility payment rate — see the Site of Service comparison table on this page. The physician's professional fee RVUs are the same regardless of site.

06What ICD-10 diagnoses most commonly support medical necessity for 26492?

Median nerve palsy (G54.1, G56.1x), thenar muscle atrophy, and traumatic nerve injury sequelae are the most common. The diagnosis must reflect a functional opposition deficit, not just a structural finding.

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 graft donor site, harvest technique, transfer routing path, fixation method, and the specific opposition deficit driving the case — all from dictation. That prevents the two most common denials: upcoding flags when harvest details are absent, and downcoding to 26490 when the free graft isn't explicitly described in the operative note.

See how Mira captures CPT 26492 documentation