Open surgical division of a single hamstring tendon anywhere along the knee-to-hip segment.

Verified May 8, 2026 · 7 sources ↓

Medicare: $420.85
Total RVUs: 12.6
Global, days: 90
Region: Knee

Drawn from CMSAAPCEmednyAbosFastrvu

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Identify the specific tendon(s) released by anatomic name (semitendinosus, semimembranosus, or biceps femoris) — 'hamstring tendon' alone is insufficient.
Confirm the open surgical approach explicitly; notes that omit approach type are vulnerable to downcoding to percutaneous (27306).
Document the surgical indication — spasticity, contracture, tendinopathy, or other diagnosis — with matching ICD-10 code to support medical necessity.
Record the anatomic level of the incision (knee region vs. proximal thigh vs. ischial area) to support 27390 vs. adjacent code families.
Note the number of tendons released; a single-tendon release is required for 27390 — any additional tendon documented forces a code change to 27391.
Include laterality (left vs. right) in both the operative note and the claim; absence triggers LT/RT modifier rejections with many payers.

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 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 27390 covers an open tenotomy of a single hamstring tendon — semitendinosus, semimembranosus, or biceps femoris — performed through a direct incision anywhere from the knee to the hip. 'Open' is the operative word: if the surgeon uses a percutaneous approach instead, that maps to 27306. The distinction must be explicit in the operative note.

The procedure carries a 90-day global period. All routine post-op visits, wound checks, and stitch removals within that window are bundled. Separate E&M visits during the global require modifier 24 (unrelated) or modifier 25 (separate, significant problem on the same day as a minor procedure — uncommon at 90-day global cases but possible if a distinct problem is addressed at the pre-op visit).

If multiple tendons are released on the same leg in the same session, step up to 27391. Bilateral multi-tendon release bills under 27392. Billing 27390 with modifier 50 is incorrect — use 27392 for bilateral single-tendon release or confirm code selection with your payer. Related family codes include 27393–27395 for hamstring lengthening and 27306–27307 for percutaneous approaches.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	5.39
Practice expense RVU	6.16
Malpractice RVU	1.05
Total RVU	12.6
Medicare national rate	$420.85
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	$420.85
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 27390 get rejected.

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

Percutaneous approach documented instead of open, mapping the claim to 27306 and triggering a down-code or denial.
Multiple tendons named in the operative note while 27390 (single tendon) is billed — payers flag the mismatch on review.
Missing or non-specific ICD-10 diagnosis code that fails to establish medical necessity for surgical tendon release.
Claim submitted without LT or RT modifier when payer policy requires laterality on all unilateral lower-extremity procedures.
Routine post-op E&M billed within the 90-day global period without modifier 24 or 25, resulting in automatic denial.

Frequently asked questions

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

01What separates 27390 from 27306?

Approach. 27390 is an open tenotomy requiring a skin incision and direct visualization. 27306 is percutaneous — no open exposure. If your operative note describes a direct incision, 27390 is correct. If it describes a stab incision or blind technique, use 27306.

02The surgeon released two hamstring tendons on the same leg — is 27390 still correct?

No. Two or more tendons on one leg in the same session maps to 27391. Billing 27390 when the note names two tendons is a code mismatch and will fail on post-payment audit.

03Can 27390 be billed bilaterally with modifier 50?

The code family handles bilaterality through 27392, which covers multiple tendons on both legs. If the surgeon released a single tendon on each side, confirm with your payer whether 27392 or 27390-50 is preferred — payer policy varies here. 27392 is the cleaner choice.

04What is the global period for 27390, and what does it include?

90 days. The global covers the surgery, the day-before visit, and all routine post-op care through day 90. Separate E&M visits for unrelated problems during that window need modifier 24. A new and distinct problem addressed on a different claim date needs modifier 79.

05How does 27390 differ from 27393?

27390 is a tenotomy — the tendon is surgically divided or cut. 27393 is a lengthening — the tendon is elongated (e.g., Z-lengthening) without complete division. The operative technique must match the code. Auditors will compare the note's description to the billed code.

06Is modifier 22 ever appropriate with 27390?

Yes, when documented complexity significantly exceeds the typical procedure — for example, dense adhesions from prior surgery, unusual anatomy, or markedly increased operative time. Document the increased complexity explicitly in the operative note with estimated additional time. Modifier 22 without supporting documentation is routinely denied.

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 named tendon(s) released, the open approach, incision level along the knee-to-hip segment, and laterality directly from dictation — the four data points auditors check first when a 27390 claim is reviewed. Capturing these in the operative note at the time of dictation prevents the most common denial: open vs. percutaneous approach ambiguity that maps the claim to the lower-value 27306.

See how Mira captures CPT 27390 documentation