Secondary repair of the extensor tendon's central slip at the proximal interphalangeal joint using a free graft, performed to correct boutonniere deformity and restore active finger extension. Graft harvest is included in the code.

Verified May 8, 2026 · 6 sources ↓

Medicare: $789.26
Total RVUs: 23.63
Global, days: 90
Region: Hand

Drawn from CMSAAPCFindacodeGenhealthNIH

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify that this is a secondary (not acute/primary) repair and document chronicity of the deformity
Name the deformity being corrected (boutonniere deformity) and confirm PIP involvement of the central slip
Identify the specific finger being repaired using standard digit nomenclature
Document the graft source, graft type, and harvest technique used
Describe the condition of the tendon ends and any scar tissue excised prior to grafting
Record failed or completed conservative treatment (splinting, therapy) that preceded surgical indication

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

26428 covers a secondary (not acute) repair of the central slip of the extensor tendon — the structure that crosses the PIP joint and enables full finger extension. The defining feature of this code versus a primary repair is that it addresses chronic disruption, typically boutonniere deformity, where the PIP joint flexes and the DIP joint hyperextends. Because functional scar and retracted tendon ends make primary re-approximation insufficient, a free graft is used to bridge or augment the central slip. Graft harvest is bundled — do not separately report 20924 or similar harvest codes.

The procedure carries a 90-day global period. All routine post-op visits, wound care, splint checks, and stitch removal through day 90 are included. If you need to bill a separate E/M in that window for an unrelated problem, append modifier 24. An unplanned return to the OR for a related complication (e.g., tendon re-rupture) bills with modifier 78; an unrelated surgical procedure in the global window uses modifier 79. The code is reported per finger — if multiple fingers require repair in the same session, report 26428 for each finger with modifier 51 on secondary procedures and digit-specific modifiers (FA–F9) to identify which finger.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	7.22
Practice expense RVU	14.89
Malpractice RVU	1.52
Total RVU	23.63
Medicare national rate	$789.26
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	$789.26
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 26428 get rejected.

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

Missing or inadequate documentation of chronicity — payers remap to primary repair code 26426 when secondary nature is not clearly stated
Graft harvest code billed separately when harvest is already bundled into 26428
Digit-specific modifier (FA–F9) absent, triggering claim suspension or medical review for laterality/specificity
Procedure billed during global period of a prior hand surgery without modifier 78 or 79, flagged as duplicate
ICD-10 diagnosis does not support central slip pathology or boutonniere deformity (M20.02x series)

Frequently asked questions

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

01What is the difference between 26426 and 26428?

26426 covers secondary repair of the central slip without a graft. 26428 is used when a free graft is required — typically because the tendon is too retracted, attenuated, or scarred to repair without interpositional tissue. The graft harvest is included in 26428; do not add a separate harvest code.

02Do I need a digit modifier with 26428?

Yes. Append FA through F9 to identify the specific finger. Omitting the digit modifier invites medical review and is a common reason for claim suspension, especially when multiple fingers are billed on the same date.

03Can I bill graft harvest separately when reporting 26428?

No. Graft harvest is bundled into 26428 by code definition. Separately reporting 20924 or another harvest code will be denied under NCCI bundling edits.

04What modifier applies if the patient returns to the OR during the 90-day global for re-rupture of the repaired tendon?

Use modifier 78 — unplanned return to the OR for a related procedure during the postoperative period. Modifier 79 is for unrelated procedures only; inverting the two is a compliance risk.

05Is 26428 billable bilaterally in the same session?

Yes, if boutonniere deformity is corrected on fingers of both hands in one session. Report 26428 with modifier 50 (or LT/RT) and the appropriate digit modifiers. Some payers require separate line items with LT and RT instead of modifier 50 — verify payer preference before submitting.

06What ICD-10 diagnoses support 26428?

Boutonniere deformity (M20.021–M20.029) is the primary supporting diagnosis. Traumatic or post-surgical central slip disruption coded from the S-series may also apply depending on chronicity. The diagnosis must reflect chronic or secondary pathology — an acute traumatic code alone will not support a secondary repair.

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 chronicity of the tendon injury, the specific deformity type (boutonniere), the finger involved, graft harvest site and technique, and the condition of the central slip at time of repair. That prevents the most common audit flag on 26428 — operative notes that read as an acute primary repair, which prompt recode to 26426 and a significant payment reduction.

See how Mira captures CPT 26428 documentation