Open repair of intrinsic or extrinsic muscles of the hand, performed to restore motor function lost due to injury, disease, or prior failed repair.

Verified May 8, 2026 · 6 sources ↓

Medicare: $492.33
Total RVUs: 14.74
Global, days: 90
Region: Hand

Drawn from CMSBedrockbillingAAOSAoassn

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Identify each muscle repaired by name and anatomical location (e.g., first dorsal interosseous, abductor digiti minimi)
Describe the mechanism of injury or underlying pathology necessitating repair
Document the surgical approach and technique used to reapproximate or reconstruct muscle tissue
State pre-operative functional deficit and intraoperative findings that confirm muscle disruption
If modifier 22 is appended, quantify the additional work — scarring grade, operative time extension, or other complicating factors — directly in the operative note
Distinguish clearly from any concurrent tendon repair to support separate billing if applicable

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 51 Multiple procedures 57 Decision for surgery 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 26591 covers open surgical repair of hand muscles — typically intrinsic muscles such as the interossei or hypothenar group — when disruption has caused functional deficits that cannot be managed conservatively. This is a distinct procedure from tendon repair (26350–26418 range) and requires documentation that identifies the specific muscle(s) involved, the mechanism of injury or disease process, and the surgical technique used to reapproximate or reconstruct the muscle tissue.

The 90-day global period means all routine postoperative care through day 90 is included in the payment. A pre-operative E/M on the day before surgery requires modifier 57. Any return to the OR within the global for a related complication uses modifier 78; an unrelated procedure uses modifier 79. If the complexity of the repair was substantially greater than typical — extensive scarring, multilevel involvement, or a hostile wound bed — modifier 22 applies, but the operative note must explicitly quantify the additional work.

Site of service matters here: HOPD and ASC payments differ significantly (see the Site of Service comparison table). Payers may scrutinize whether this code is appropriately distinguished from tendon repair codes billed on the same date — if both a muscle repair and a tendon repair were performed, clear documentation of each structure must support separate billing with modifier 59 or XS.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	3.3
Practice expense RVU	10.82
Malpractice RVU	0.62
Total RVU	14.74
Medicare national rate	$492.33
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	$492.33
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 26591 get rejected.

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

Operative note documents 'muscle repair' generically without identifying the specific muscle(s), triggering medical necessity denials
Bundling conflict when 26591 is billed same-day as tendon repair codes without modifier 59 or XS to establish distinct procedural service
Modifier 22 appended without supporting documentation quantifying why the work was substantially greater than typical
Post-operative E/M billed without modifier 24 during the 90-day global period, resulting in automatic denial as included service
Incorrect site-of-service indicator causing payment at the wrong fee schedule rate

Frequently asked questions

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

01How does 26591 differ from hand tendon repair codes?

26591 covers repair of muscle tissue itself — interossei, hypothenar, or thenar muscles. Tendon repair codes (e.g., 26350–26418) cover the tendinous structures. If both a muscle and a tendon were repaired in the same session, document each structure separately and append modifier 59 or XS to the secondary code to defeat the NCCI bundle.

02Can I bill a same-day E/M with 26591?

Only if the E/M addressed a separate, distinct problem and you append modifier 25. If the visit was solely to decide on and plan the repair, it's bundled into the procedure. If the decision for this major (90-day global) surgery was made at a visit the day of or day before surgery, use modifier 57 on the E/M instead.

03When does modifier 22 apply to 26591?

Use modifier 22 when the repair required substantially more work than typical — for example, extensive fibrous scarring requiring takedown, a contaminated or previously operated field, or multilevel muscle involvement. The operative note must explicitly describe and quantify the extra work. A modifier 22 without supporting narrative will be reversed on audit.

04What happens if I need to return to the OR during the 90-day global?

Use modifier 78 if the return is for a complication or issue related to the original muscle repair. Use modifier 79 if the procedure is entirely unrelated to 26591. Do not invert these — a 78 on an unrelated procedure will misrepresent the clinical situation and can trigger a recoupment.

05Does the site of service affect reimbursement for 26591?

Yes. HOPD and ASC payments differ substantially — see the Site of Service comparison table on this page. The physician's professional fee also adjusts based on facility vs. non-facility setting through the practice expense RVU component. Confirm your service location is correctly reported on the claim.

06Is 26591 billable bilaterally?

If muscle repairs are performed on both hands in the same operative session, bill 26591 twice with modifier 50, or once with LT and once with RT depending on your payer's preference. List the higher-complexity side first. Confirm bilateral coverage policy with each payer before submitting — some commercial contracts require specific bilateral billing formats.

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 specific muscle repaired by name, the intraoperative findings confirming disruption, the surgical technique used, and any complicating factors such as scarring or hostile wound bed from the surgeon's dictation. That level of specificity prevents the generic 'muscle repair' documentation that audit teams flag and that payers cite when denying medical necessity on 26591 claims.

See how Mira captures CPT 26591 documentation