CPT® Code 27592

Quick Reference

• Code definition: CPT 27592 reports an open, circular (guillotine) amputation of the thigh through the femur at any level, where soft tissue and bone are transected in a single circular pass and the wound is intentionally left open for staged closure.
• Always staged: This code represents the first stage of a two-step procedure. The wound is never closed at this encounter. Secondary closure (27594) or re-amputation (27596) must be billed separately with modifier -58.
• Modifier -58 is mandatory: When the same surgeon performs 27594 or 27596 within the 90-day global period of 27592, modifier -58 is required on the follow-up code. Omitting -58 triggers denial as a bundled global service.
• Inpatient-only under Medicare: 27592 carries an "Inpatient Procedures, not paid under OPPS" APC status indicator. Medicare will not pay this code for outpatient or ASC encounters. Confirm inpatient admission status before billing.
• Documentation must-have: The operative report must explicitly state why formal closure was deferred (contamination, sepsis, hemodynamic instability) and confirm the circular incision technique with the wound left open at the end of the case.
• Top confusion point: Selecting 27590 when the operative report describes an open wound left for staged closure is the most audited error in this code family. Technique documented in the op note, not the planned approach, determines code selection.
• Surgeon modifiers: No statutory restriction applies to assistant surgeons (modifier -80 or -82 permitted). Co-surgeons (modifier -62) are permitted with supporting documentation of medical necessity. Team surgery (modifier -66) is not permitted.

When to Use This Code

CPT 27592 applies when a surgeon performs an amputation through the femur using a circular incision technique, transecting skin, muscle, and bone without fashioning skin flaps, and deliberately leaves the wound open at the end of the procedure. The defining feature is the open wound, not merely the circular incision.

Clinical scenarios that drive 27592:

• Severe traumatic injuries with gross wound contamination (blast, crush, agricultural injuries) where primary closure would risk invasive infection or gas gangrene
• Necrotizing soft tissue infections or clostridial myonecrosis requiring emergent source control ahead of any formal reconstruction
• Septic patients with critical vascular compromise who cannot physiologically tolerate the extended operative time required for flap creation and wound closure
• Non-viable limbs with extensive tissue destruction where the full extent of debridement cannot be determined intraoperatively

Scope boundaries:

The code covers any femoral level (proximal, mid, or distal third). Level selection is dictated by the extent of injury or infection at the time of surgery, not by prosthetic planning considerations (which would push toward definitive closure codes). The procedure includes all incision work, soft tissue transection, vessel ligation, nerve transection, and femoral osteotomy. Wound packing and dressing application are included in the global package.

Provider and setting context:

27592 is performed in the inpatient operating room. Vascular surgery, orthopedic surgery, or general surgery may perform the procedure. Co-surgeon participation (modifier -62) is common in complex trauma or when both vascular and orthopedic expertise is required simultaneously, and is supported when two surgeons contribute distinct operative work [1].

Code Differentiation Table

The 27590 to 27596 family shares a single anatomical site (femur) but codes for fundamentally different surgical techniques and stages. Selecting the wrong code within this family is the primary audit trigger for thigh amputation claims [1].

The critical differentiator between 27592 and 27590 is wound closure status at the end of the operative session. If the operative report documents skin flaps raised and closed, 27590 applies regardless of how the circular incision was executed. If the report states "wound left open," "wound packed," or "return to OR planned for closure," 27592 is correct.

flowchart TD
    A[Amputation through femur documented] --> B{Was wound closed at end of this session?}
    B -->|Yes, with flaps| C{Immediate prosthetic cast applied?}
    B -->|No, intentionally left open| G[27592]
    C -->|Yes| D[27591]
    C -->|No| E[27590]
    G --> F{Follow-up procedure during 27592 global period?}
    F -->|Yes, closure or revision| H[27594 plus modifier -58]
    F -->|Yes, re-amputation at higher level| I[27596 plus modifier -58]

Billing & Modifier Rules

Modifier -58 (staged procedure): When the same surgeon performs 27594 or 27596 within the 90-day global period of 27592, modifier -58 is required on the follow-up code. Modifier -58 signals the procedure was planned or anticipated at the time of the first surgery, opens a new 90-day global period for the second procedure, and allows separate payment. This is not optional; it is mandatory for any same-surgeon staged follow-up within the global window [2].

Modifier -78 vs modifier -58: These are not interchangeable. Modifier -78 applies only to an unplanned return to the OR for a complication during the global period. Because return for closure or re-amputation after a guillotine amputation is always anticipated, modifier -58 applies exclusively. Using -78 for a planned second stage does not open a new global period and will result in reduced payment [2].

Co-surgeons (modifier -62): Permitted for 27592 with documentation of medical necessity. Both surgeons submit 27592 with modifier -62. Each surgeon's operative note must describe their distinct contribution. Common co-surgeon scenarios include simultaneous vascular and orthopedic participation in complex trauma or infection cases.

Assistant surgeon (modifiers -80, -82): No statutory restriction applies to 27592. An assistant surgeon may be paid. Payer-specific coverage policies apply; verify commercial payer billing rules before submitting modifier -80 or -82.

Laterality modifiers (LT, RT): Apply LT or RT to all codes in the 27590 to 27596 family when laterality is documented. These modifiers are critical when billing separate encounters on the same limb during a global period.

Modifier -22 (increased procedural services): Applicable when operative complexity substantially exceeds what is typical, for example morbid obesity, prior multiple surgeries at the same site, or severe vascular calcification requiring extended operative time. Requires detailed narrative documentation and a cover letter supporting the additional work.

Modifier -50 (bilateral): 27592 carries a bilateral surgery indicator of 1, meaning a 150% payment adjustment applies for bilateral thigh amputation performed in the same session. Bilateral thigh amputation is clinically uncommon, but the modifier pathway is available [1].

Modifier -54/-55 (split post-operative care): If a different surgeon will provide post-operative management (common when a trauma surgeon performs the emergent guillotine but an orthopedic team manages recovery), the operating surgeon bills 27592-54 and the post-operative surgeon bills 27592-55.

MUE = 1: Only one unit of 27592 may be billed per date of service per patient. This is a date-of-service MUE with adjudication indicator 2; modifiers -59 or XS/XU cannot override it [3].

Bundled services: Wound debridement at the same operative site on the same date of service, wound closure codes (12001 to 13321), and all incision and approach work are included in the global surgical package and cannot be separately reported. Same-day E/M services by the operating surgeon are bundled unless a separately identifiable service was provided before the decision to operate (use modifier -25 on the E/M code).

Documentation Essentials

The operative report for 27592 must go beyond standard surgical documentation to specifically support both the guillotine technique and the rationale for deferred closure. Auditors reviewing 27592 claims concentrate on four areas [4][5].

Required documentation elements:

• Indication and diagnosis: The specific condition (trauma with contamination, gangrene, osteomyelitis, malignancy) with corresponding ICD-10-CM codes linked on the claim
• Reason for guillotine technique over definitive closure: Explicit statement explaining why formal flap closure (27590) was contraindicated, such as "wound too contaminated for primary closure," "patient hemodynamically unstable," or "gas gangrene requiring emergent source control"
• Circular incision technique: Description of the circular skin incision, soft tissue allowed to retract, and bone transected at the level of retracted muscle
• Level of femoral transection: Proximal, mid, or distal third of the femur
• Wound management at end of case: Confirmation the wound was left open, with packing applied or negative pressure wound therapy initiated
• Staged plan: Documentation that a second procedure is anticipated, such as "patient will return to OR once infection controlled"
• Supporting pre-operative studies for vascular cases: Ankle-brachial index (ABI), duplex ultrasound, or angiography confirming non-reconstructable disease; prior revascularization attempts if applicable

Audit red flags specific to 27592:

• Operative note describes open wound left for staged closure but claim billed as 27590
• Second-stage procedure (27594 or 27596) billed within the global period without modifier -58, triggering automatic denial as a bundled service
• Absence of any documentation explaining why formal closure was deferred
• Non-specific gangrene code (I96) used when a more specific combination code is available, such as I70.261 for atherosclerosis with gangrene of the right leg or E11.52 for Type 2 diabetes with diabetic peripheral angiopathy with gangrene
• Post-operative E/M visits billed within the 90-day global period without modifier -24 or -79

Medicare, Commercial & Medicaid Payer Rules

Medicare:

CPT 27592 carries an APC status indicator of "Inpatient Procedures, not paid under OPPS." Medicare will not pay 27592 for hospital outpatient or ambulatory surgery center encounters. The procedure must be performed and billed as an inpatient hospital admission. Submitting this code on an outpatient or ASC claim to Medicare will result in denial [1].

No National Coverage Determination exists specifically for thigh amputation. Coverage is determined on a medical necessity basis, defaulting to MAC discretion. MACs generally require documentation of failed limb salvage or revascularization for vascular indications, non-reconstructable vascular disease confirmed by imaging, tissue non-viability for infectious or traumatic indications, or multidisciplinary oncologic evaluation for malignancy.

Note the contrast with 27594 (secondary closure): unlike 27592, the secondary closure code carries a comprehensive APC status and is payable in the ASC setting. When billing the two-stage sequence, the first stage (27592) requires inpatient admission; the second stage (27594 or 27596) may follow different payment rules depending on the setting in which it is performed.

The 90-day global period includes all related post-operative care by the operating surgeon. Post-operative visits, wound checks, and related E/M services are bundled and may not be separately billed unless a modifier (-24, -79) documents an unrelated service [2].

Commercial payers:

Most commercial payers follow Medicare payment rules for surgical global periods and modifier usage. Prior authorization is typically required for inpatient surgical procedures including amputation. For elective or semi-elective cases, verify PA requirements before scheduling. Some commercial payers apply automated claim edits that bundle 27592 with same-day wound debridement codes; if debridement was performed at a separate anatomical site on the same date, append the appropriate X-modifier with documentation supporting the distinct service.

Medicare Advantage (Part C):

Medicare Advantage plans require plan-specific prior authorization for most inpatient surgical procedures. Even in emergent cases, retrospective notification requirements may apply. Confirm the plan's PA and notification protocols, as denial for failure to notify is common in MA claims [1].

Medicaid:

State-specific prior authorization requirements apply to inpatient surgery under Medicaid. Many states require PA for inpatient surgical procedures. Managed Medicaid plans may impose additional documentation requirements beyond fee-for-service Medicaid. Verify state-specific rules for each encounter.

Common Denials & Prevention

Denial: Bundled into global surgical package

The second-stage procedure (27594 or 27596) is denied as included in the 90-day global period of 27592. This happens when modifier -58 is omitted on the follow-up claim.

Prevention: Bill all same-surgeon staged follow-up procedures within the 27592 global period with modifier -58 appended to the follow-up code. Track all 27592 dates of service to maintain awareness of active global periods and prompt timely modifier application [2].

Denial: Inpatient-only procedure billed for outpatient encounter

Medicare denies 27592 when submitted on a hospital outpatient or ASC claim. This is a common error when the case begins as an outpatient evaluation and the patient is taken emergently to surgery without a formal inpatient admission order being documented.

Prevention: Confirm inpatient admission status in the facility's ADT system before submitting the professional claim. For emergent cases, coordinate with the facility to verify the admission order was placed and the encounter is classified as inpatient [1].

Denial: Wrong code selected within family

Payer audits identify claims where 27592 is billed but the operative report describes flap creation and wound closure consistent with 27590, or conversely where 27590 is billed for an open wound.

Prevention: Read the operative report before code assignment, focusing specifically on wound closure technique and whether the stump was closed or left open. If the op note is ambiguous, query the physician before billing.

Denial: Medical necessity not established

The claim is denied for insufficient documentation supporting the need for amputation, particularly for vascular indications where limb salvage alternatives exist.

Prevention: Ensure the medical record documents prior treatment attempts (revascularization, debridement, wound management), supporting imaging studies (ABI, angiography), and a clear statement from the operating surgeon explaining why limb salvage was not feasible [5].

Denial: Non-specific diagnosis coding

The claim lacks diagnosis specificity, for example using I96 (gangrene, not elsewhere classified) when a combination code with the underlying etiology and complication is available and better supported by the record.

Prevention: Sequence diagnosis codes to the highest level of specificity the medical record supports. For diabetic gangrene, use the applicable combination code (e.g., E11.52 for Type 2 diabetes with diabetic peripheral angiopathy with gangrene). For vascular gangrene, use the specific atherosclerosis with gangrene code (e.g., I70.261 for right leg).

Coding Scenarios

Scenario 1: Traumatic guillotine amputation, first stage

A 34-year-old male sustains a crush injury to the left thigh from industrial machinery with extensive soft tissue destruction and gross contamination. The surgeon performs emergent mid-femur amputation using a circular incision, leaving the wound open and packed. No skin flap closure is attempted.

Correct coding: 27592-LT + S78.112A (Complete traumatic amputation at level between left hip and knee, initial encounter)

Why: The wound was intentionally left open, confirming the guillotine technique (27592) rather than definitive closure (27590). When the same surgeon performs stump closure 10 days later, bill 27594-LT-58.

Scenario 2: Diabetic gangrene, staged approach with mandatory modifier -58

A 67-year-old female with Type 2 diabetes and peripheral arterial disease develops wet gangrene of the right foot that has progressed proximally to the thigh. Vascular surgery performs a guillotine amputation through the right femur due to sepsis and hemodynamic instability. The same surgeon performs formal stump revision and closure two weeks later.

Stage 1: 27592-RT + E11.52 (Type 2 diabetes with diabetic peripheral angiopathy with gangrene), I70.261 (atherosclerosis with gangrene, right leg)

Stage 2: 27594-RT-58

Why: Modifier -58 is mandatory on 27594 because the second procedure was planned at the time of 27592 and falls within the 90-day global period. Modifier -58 opens a new 90-day global period for the closure procedure [2].

Scenario 3: Gas gangrene, co-surgeons

A 58-year-old male with clostridial myonecrosis of the left thigh undergoes emergent guillotine amputation. The extent of tissue involvement requires both an orthopedic surgeon (performing the bony transection) and a general surgeon (managing soft tissue debridement and vascular control) to participate simultaneously in distinct operative portions.

Correct coding: Both surgeons bill 27592-LT-62 + A48.0 (Gas gangrene), M72.6 (Necrotizing fasciitis)

Why: Modifier -62 applies when two surgeons perform distinct portions of the same procedure. Each surgeon's operative note must describe their specific contribution, and the documentation must support why co-surgeon participation was medically necessary [1].

Scenario 4: Re-amputation at higher level with modifier -58

Following a right femur guillotine amputation (27592) for necrotizing osteomyelitis, wound cultures three weeks later reveal proximal extension of infection. The same surgeon re-amputates at a higher femoral level.

Correct coding: 27596-RT-58 + M86.151 (Other acute osteomyelitis, right femur)

Why: The re-amputation is a staged procedure within the 27592 global period, requiring modifier -58. Modifier -58 opens a new 90-day global from the date of 27596. Using modifier -78 here would be incorrect; the return was anticipated, not an unplanned complication [2].

Related Codes

• 27590 (CPT): Amputation, thigh, through femur, any level; definitive amputation with wound closure at the primary session
• 27591 (CPT): Amputation, thigh; immediate fitting technique including first cast; definitive closure with prosthetic cast at the primary session
• 27594 (CPT): Amputation, thigh; secondary closure or scar revision; planned second stage after 27592, bill with modifier -58
• 27596 (CPT): Amputation, thigh; re-amputation; higher-level re-amputation after 27592, bill with modifier -58
• 27295 (CPT): Hip disarticulation; proximal-level amputation used when 27592 stump fails and further proximal resection is required
• 27882 (CPT): Amputation, leg, through tibia and fibula; open circular (guillotine); below-knee anatomical equivalent of 27592
• 27598 (CPT): Disarticulation at knee; adjacent anatomical level, separate code range, inpatient-only under Medicare

Sources

1. CMS Physician Fee Schedule Look-Up Tool — CMS, 2025 — RVU values, global days, modifier indicators, APC status, and surgical indicator fields for CPT 27590 to 27598.
2. CMS Global Surgery MLN Booklet (MLN006974) — CMS, current — Global surgical package inclusions and exclusions; modifier -58 vs modifier -78 guidance; staged procedure billing rules.
3. CMS NCCI Medically Unlikely Edits (MUEs) — CMS, quarterly updated — MUE value of 1 for CPT 27592 with date-of-service adjudication indicator 2.
4. CMS Medicare Claims Processing Manual, Chapter 12 — CMS, current — Global surgery rules, documentation requirements, teaching physician rules, and billing requirements for physicians and NPPs.
5. HHS OIG Work Plan, Surgical Procedures — HHS OIG, annual — Amputation billing compliance; lower extremity surgical procedure audit focus areas; upcoding and global period unbundling risk areas.