Transfer of hamstring tendon or muscle to the femur, typically performed to address spastic muscle imbalance — classic indication is cerebral palsy.

Verified May 8, 2026 · 6 sources ↓

Medicare: $659.00
Total RVUs: 19.73
Global, days: 90
Region: Knee

Drawn from CMSAbosAAPCFindacodeCgsmedicare

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Diagnosis driving the transfer — specify underlying condition (e.g., spastic diplegia, cerebral palsy) with supporting ICD-10
Named procedure and surgical approach — document 'hamstring tendon transfer to femur, Eggers-type' or equivalent; avoid generic 'muscle transfer' language
Specific tendon(s) transferred — identify semitendinosus, semimembranosus, or biceps femoris by name and whether single or multiple tendons
Laterality — left, right, or bilateral; must match claim line modifiers exactly
Intraoperative tension setting and fixation method at the new femoral insertion point
Pre-op functional assessment documenting crouch gait, spasticity grade, or motion-analysis findings that support surgical indication

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 58 Staged or related 59 Distinct service 62 Co-surgeons 74 Discontinued post-anesthesia 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 27400 covers open transfer of a hamstring tendon or muscle to the femur — the canonical example being the Eggers-type procedure used to correct spastic crouch gait in patients with cerebral palsy. The surgeon detaches one or more hamstring tendons from their distal insertion and reattaches them proximally at the femur, converting their action from knee flexion to hip extension. The procedure requires full open exposure of the distal thigh and meticulous tendon handling to achieve correct tension at the new insertion point.

The 90-day global period governs all post-op management: routine follow-up visits, gait assessments, and cast or brace checks through day 90 are bundled. Bill unrelated problems in the global window with modifier 24. If a staged or planned secondary procedure is needed within the global, modifier 58 applies; an unplanned return to the OR for a related complication uses modifier 78.

Bilateral transfers are common in CP patients. When performed on both legs during the same operative session, append modifier 50 and confirm payer policy — some require two line items with LT/RT instead. Document each limb separately in the operative note. The top billing specialty in CMS PUF data is Plastic and Reconstructive Surgery, though orthopedic and pediatric orthopedic surgeons perform this procedure regularly; specialty mismatch rarely triggers denial but can draw audit attention.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	9.1
Practice expense RVU	8.69
Malpractice RVU	1.94
Total RVU	19.73
Medicare national rate	$659.00
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	$659.00
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI A2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 27400 get rejected.

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

Medical necessity not established — payer requires documented failure of conservative management (PT, bracing, botox) before approving open tendon transfer
Bilateral billed incorrectly — modifier 50 rejected by payers requiring separate LT/RT line items; or bilateral not pre-authorized
Diagnosis-to-procedure mismatch — ICD-10 code does not clearly link spastic or neuromuscular etiology to femoral transfer necessity
Global period conflict — post-op visit or repeat procedure billed without appropriate modifier 24, 58, or 78 during the 90-day window
Site-of-service mismatch — procedure billed under facility RVUs but performed at non-facility site, or vice versa

Frequently asked questions

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

01Can 27400 be billed bilaterally in a single operative session?

Yes. Bilateral hamstring transfers in the same session are common for CP patients. Append modifier 50 on a single line or use separate LT and RT lines — confirm your payer's preference before submitting. Medicare generally accepts modifier 50 with a single line item.

02What ICD-10 codes support 27400?

Spastic cerebral palsy codes (G80.0, G80.1) are the primary drivers. Acquired spastic conditions affecting gait may also apply. The diagnosis must clearly establish a neuromuscular or spastic etiology; a generic 'muscle weakness' code will likely trigger a medical necessity denial.

03Is 27400 ever performed for non-CP indications?

Yes, though less commonly. Hamstring-to-femur transfer can address chronic hamstring avulsion with retraction or neuromuscular conditions beyond CP. Documentation must tie the specific biomechanical deficit to the femoral transfer technique — payers scrutinize non-CP claims more closely.

04How does the 90-day global period affect post-op physical therapy orders?

The global bundles the surgeon's routine post-op visits — it does not bundle PT billed by a separate therapist. The surgeon's own reassessment visits during the 90 days are included. If the surgeon identifies and manages a new, unrelated problem at a post-op visit, bill with modifier 24 and document clearly that the visit addressed an issue distinct from the transfer recovery.

05Can 27400 be billed same-day with hamstring tenotomy codes like 27390 or 27391?

Only if a distinct, separately documented procedure was performed on a different tendon. NCCI edits bundle closely related hamstring procedures. Use modifier 59 (or XS for separate structure) with robust operative note documentation showing the two procedures addressed anatomically distinct tendons and were not components of the same repair sequence.

06Why does CMS PUF show Plastic and Reconstructive Surgery as the top billing specialty for 27400?

Pediatric plastic surgeons manage CP musculoskeletal sequelae in some regions and health systems. Orthopedic and pediatric orthopedic surgeons also perform this code frequently. Specialty mismatch is not itself a denial trigger, but it can flag a claim for review — ensure documentation supports the surgeon's training and scope.

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) transferred, laterality, surgical approach, femoral fixation technique, and intraoperative tension documentation directly from dictation. This prevents the two most common audit flags for 27400: operative notes that omit which specific hamstring tendon was moved and notes that fail to name the underlying neuromuscular diagnosis — both of which draw medical necessity scrutiny from payers and RAC auditors.

See how Mira captures CPT 27400 documentation