Surgical lengthening or shortening of a single tendon in the lower leg or ankle to correct contracture, acquired deformity, or functional impairment.

Verified May 8, 2026 · 7 sources ↓

Medicare: $681.71
Total RVUs: 20.41
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCFindacodeAbosAAOS

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify which tendon was revised by anatomic name (e.g., Achilles, posterior tibial, peroneal brevis) — notes that say 'leg tendon' without identification invite audits.
State the direction of revision: lengthening (e.g., Z-plasty, step-cut) or shortening, and the technique used.
Document the clinical indication: contracture, deformity, or functional deficit, with pre-op exam findings supporting the medical necessity.
Record intraoperative tendon length measurements or tension assessments when available — supports medical necessity and distinguishes from tenolysis.
If performed with an osteotomy or other concurrent procedure, include a separate description of each distinct surgical step with its own wound or incision details.
Note the approach: open incision location, length, and layers traversed — avoids confusion with arthroscopic or percutaneous techniques.

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 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 27685 covers open surgical revision of a leg or ankle tendon — either lengthening a shortened, contracted tendon or shortening one that has become functionally lax — to restore biomechanical function and relieve pain. The code applies to a single tendon; if multiple tendons require revision through separate incisions, each is reported separately. Common clinical indications include equinus contracture, spastic deformity, and post-traumatic or congenital tendon length discrepancy. The Achilles tendon is frequently involved, but the code applies to any leg or ankle tendon when the procedure involves a length-altering revision rather than primary repair or tenolysis.

With a 90-day global period, all routine postoperative care through day 90 is bundled. Unrelated E/M services within the global window require modifier 24; a separately identifiable E/M on the day of surgery requires modifier 25. If a concomitant procedure such as a calcaneal osteotomy (e.g., 28300) is performed, check NCCI PTP edits before billing both codes and apply modifier 59 or XS only if the procedures are genuinely distinct and separately documented. Do not confuse 27685 with tenolysis codes 27680–27681 (adhesion release only) or primary repair codes 27658–27665 — the operative note must clearly describe length alteration, not just release or suture repair.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	6.52
Practice expense RVU	12.97
Malpractice RVU	0.92
Total RVU	20.41
Medicare national rate	$681.71
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	$681.71
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 27685 get rejected.

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

Upcoding or miscoding: payers downcode to tenolysis (27680) when the operative note describes adhesion release without clear documentation of length alteration.
Bundling denial when billed same-day with a concurrent calcaneal osteotomy or other foot/ankle procedure without a modifier establishing separate and distinct service.
Lack of medical necessity: no documented functional deficit, contracture severity, or failed conservative treatment in the pre-op record.
Global period conflict: postoperative E/M visits billed without modifier 24 within the 90-day global window are automatically denied.
Incorrect tendon specificity: operative note identifies only 'Achilles' but clinical context suggests involvement of multiple tendons — payer questions single-tendon billing.

Frequently asked questions

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

01Can 27685 be billed for both the Achilles and the posterior tibial tendon in the same operative session?

Yes — 27685 is a per-tendon code. If two separate tendons are lengthened or shortened through distinct incisions in the same session, report 27685 twice with modifier 51 on the secondary unit. Document each tendon and its incision separately in the operative note.

02How does 27685 differ from 27680 (tenolysis)?

27680 covers adhesion release only — the tendon's length is not changed. 27685 requires an actual length-altering procedure: Z-plasty, step-cut lengthening, or plication/shortening. Payers audit this distinction closely; the operative note must describe the technique, not just 'tendon release.'

03Is a same-day calcaneal osteotomy (28300) separately billable with 27685?

Potentially yes, but check current NCCI PTP edits first. If the osteotomy and tendon revision are distinct procedures on separate anatomic structures with independent documentation, modifier 59 or XS supports separate billing. Don't append a modifier reflexively — the operative note must justify it.

04What modifiers apply if this procedure is performed bilaterally?

Use RT and LT to identify laterality, or modifier 50 if the payer accepts bilateral billing on a single line. Confirm payer preference before submitting — some commercial payers require two separate line items with RT/LT rather than modifier 50.

05Does the 90-day global period affect billing for cast changes or boot adjustments post-op?

Routine wound checks, dressing changes, and casting adjustments are bundled in the 90-day global. Separately reportable events within the global window include treatment of a new or unrelated condition (modifier 24), a significant separately identifiable service (modifier 25), or a return to the OR for a complication — related (modifier 78) or unrelated (modifier 79).

06When is modifier 22 appropriate for 27685?

Modifier 22 applies when the procedure is substantially more work than typical — for example, severe scarring from prior surgery, morbid obesity requiring extended dissection, or re-revision of a previously failed tendon lengthening. Attach a cover letter with the operative note quantifying the additional time and complexity. Payers require documentation, not just the modifier.

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 tendon name, the type of length-altering procedure (lengthening technique such as Z-plasty or step-cut versus shortening), the clinical indication, and each concurrent procedure performed through a separate incision or anatomic site. That specificity prevents downcoding to tenolysis and supports modifier 59 or XS when a same-day osteotomy or other distinct procedure is billed alongside 27685.

See how Mira captures CPT 27685 documentation