🦴 CPT 28120 — Partial Excision (Craterization, Saucerization, Sequestrectomy, or Diaphysectomy) Bone (e.g., Osteomyelitis or Bossing); Talus or Calcaneus
Quick Reference
wRVU: 7.13 | Global Period: 090 | Assistant Payable: Yes | Bilateral Indicator: 1 | Rule: Bilateral indicator 1 means the 150% bilateral payment adjustment applies when the identical procedure is performed on both feet in the same session, billed with modifier rather than -RT and -LT on separate lines. The 090-day global period is a major surgical package that bundles the pre-operative visit, the operative session, and all related post-operative E/M care for 90 days. Any unrelated E/M service during that window requires modifier, and a staged or related return to the operating room requires modifier -24 or -78.
📋 Clinical Description
CPT 28120 describes an open surgical procedure in which a surgeon removes only a portion of the talus or calcaneus — not the entire bone — to eliminate diseased, infected, or abnormally hypertrophic bone tissue.¹ The technique may involve craterization (carving out a shallow defect), saucerization (flattening/beveling the bone surface), sequestrectomy (removing a dead bone fragment, or sequestrum, in chronic osteomyelitis), or diaphysectomy (removing a segment of the bone shaft), depending on the underlying pathology.
This code sits between two related calcaneal/tarsal excision codes: 28119, which is reserved specifically for isolated calcaneal spur excision with or without plantar fascial release, and 28122, which describes an identical partial-excision technique but applies to tarsal or metatarsal bones other than the talus or calcaneus.² Unlike the more extensive 28118 ostectomy, which contemplates removal of a larger segment or the entirety of the calcaneus, 28120 is reserved for a partial, localized excision.
This procedure may be performed in the following clinical contexts:
- Chronic osteomyelitis of the calcaneus — sequestrectomy removes necrotic, infected bone (the sequestrum) to control a persistent bone infection that has failed antibiotic therapy alone.
- Chronic osteomyelitis of the talus — craterization or saucerization debrides infected talar bone following an open fracture, prior hardware infection, or diabetic foot infection extending to bone.
- Haglund’s deformity (posterior calcaneal bossing) — diaphysectomy or saucerization reduces a symptomatic posterior-superior calcaneal prominence causing retrocalcaneal bursitis and Achilles impingement.
- Post-traumatic bony prominence or exostosis of the talus — partial excision relieves pain from an osteophyte impinging on adjacent soft tissue or footwear.
- Failed conservative management of a localized benign bone lesion of the talus or calcaneus where full curettage/grafting (28100-28103) is not indicated because the defect does not require cavity filling.
🔬 Anatomical & Procedural Considerations
| Variant | Mechanism | Key Notes |
|---|---|---|
| Craterization/Saucerization | The surgeon exposes the affected bone through a direct incision and uses osteotomes or a high-speed burr to shave, bevel, or hollow out the diseased cortical/cancellous bone, leaving a smooth, saucer-shaped defect that promotes soft-tissue coverage and drainage. | Most commonly used for chronic osteomyelitis with a persistent draining sinus or for reducing a symptomatic bony prominence such as calcaneal bossing. Documentation should specify the shape and extent of bone removed. |
| Sequestrectomy | A discrete, dead bone fragment (sequestrum) that has separated from viable bone in chronic osteomyelitis is surgically located and extracted, often requiring debridement of surrounding granulation tissue and involucrum. | Culture and pathology of the excised bone are typically obtained; concurrent irrigation and debridement (CPT 11042-11047 for skin/subcutaneous debridement) may be separately reportable if performed on distinct tissue layers with documentation supporting separate work. |
| Diaphysectomy | A segment of the bone shaft (rather than the articular or cystic portion) is resected, most often used for extensive chronic osteomyelitis tracking along the bone shaft or for larger symptomatic exostoses. | Requires careful surgical planning to avoid destabilizing the talus or calcaneus; postoperative non-weight-bearing status and immobilization are common. |
Clinical Pearl
The operative note must state that the procedure was a partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) rather than complete bone removal — if the entire calcaneus is excised (calcanectomy), the more extensive 28118 ostectomy code applies instead. Documentation of the specific indication (osteomyelitis vs. bossing/exostosis) directly supports ICD-10-CM code selection and medical necessity.
✅ Procedure Includes
- Surgical exposure of the talus or calcaneus through an appropriately placed incision.
- Partial excision of diseased, infected, or hypertrophic bone using craterization, saucerization, sequestrectomy, or diaphysectomy technique.
- Debridement of adjacent nonviable soft tissue directly related to the bone excision site.
- Irrigation of the surgical site.
- Obtaining tissue/bone culture and pathology specimens when clinically indicated.
- Routine wound closure and dressing application.
- Local anesthesia or regional block administered by the operating surgeon.
❌ Excludes / Do Not Report Together
| Code | Description | Relationship |
|---|---|---|
| 28118 | Ostectomy, calcaneus (e.g., for spur or exostosis, sequestrum) | Use 28118 instead of 28120 when the entire calcaneus, or a substantially larger complete resection, is performed rather than a partial/localized excision. |
| 28100 | Excision or curettage of bone cyst or benign tumor, talus or calcaneus | Reserved for cystic/tumor curettage without the craterization/saucerization/sequestrectomy/diaphysectomy technique described by 28120; do not report both for the same lesion in the same session. |
| 28122 | Partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) bone; tarsal or metatarsal, except talus or calcaneus | Identical technique but different bone; only one of 28120/28122 applies per bone treated, though both may be billed together with modifier -24 if distinct tarsal/metatarsal bones are separately excised. |
| 20245 | Biopsy, bone, open; deep (e.g., humeral shaft, femoral shaft) | A separate open bone biopsy is not separately reportable when the biopsy tissue is obtained from the same bone and same operative session as the definitive 28120 excision. |
Bundling Alert
Because 28120 carries a 090-day global period, any subsequent debridement, wound check, or dressing change related to the same operative site during the 90-day window is bundled and not separately billable unless a new, unrelated problem arises (modifier -24) or a planned/unplanned return to the operating room occurs (modifier -24/-78/-79). Payers frequently audit claims pairing 28120 with skin debridement codes (11042-11047) on the same date of service, so operative documentation must clearly delineate distinct tissue layers and separate medical necessity to avoid an unbundling denial.
🌳 Code Tree — Surgery: Musculoskeletal System, Foot and Toes (Excision)
CPT 28100-28175 Surgery: Musculoskeletal System — Foot and Toes — Excision
│
├── 28100-28103 Excision/Curettage (Talus or Calcaneus)
│ ├── 28100 Excision or curettage of bone cyst or benign tumor, talus or calcaneus
│ └── 28103 Excision or curettage of bone cyst or benign tumor, talus or calcaneus; with allograft
│
├── 28118-28124 Ostectomy / Partial Excision
│ ├── 28118 Ostectomy, calcaneus (Global: 090)
│ ├── 28119 Ostectomy, calcaneus; for spur, with or without plantar fascial release (Global: 090)
│ ├── ▶▶ 28120 ◀◀ Partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) bone (eg, osteomyelitis or bossing); talus or calcaneus ← YOU ARE HERE (Global: 090)
│ ├── 28122 Partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) bone; tarsal or metatarsal, except talus or calcaneus (Global: 090)
│ └── 28124 Partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) bone; phalanx of toe (Global: 090)
│
└── 28160-28175 Hemiphalangectomy / Resection
├── 28160 Hemiphalangectomy or interphalangeal joint excision, toe, single
└── 28175 Resection of tarsal coalition💰 RVU & Reimbursement Profile
| Component | Value |
|---|---|
| Work RVU | 7.13 |
| Global Period | 090 |
| Bilateral Indicator | 1 (150% rule applies) |
| Assistant Surgeon | Payable with documentation of medical necessity |
| Co‑Surgeon | Not typically applicable |
| Team Surgery | Not typically applicable |
| PC/TC Split | 0 — Physician service; PC/TC split concept does not apply |
| Modifier -51 Exempt | No |
| Anesthesia | Usually performed under regional block or general/MAC anesthesia; not separately billable by the operating surgeon |
Bilateral Billing Rules
When 28120 is performed on both feet in the same operative session, report it once with modifier -24 rather than on two separate lines with -RT and -LT. Because the bilateral indicator is 1, Medicare pays 150% of the standard fee schedule amount for the bilateral claim rather than 200%. If only one side is treated, append -RT or -LT to indicate laterality even though payment is unaffected. Always verify payer-specific bilateral billing preferences, as some commercial payers require -RT/-LT on separate lines regardless of the CMS indicator.
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -RT | Right Side | Append when the procedure is performed on the right talus or calcaneus only. |
| -LT | Left Side | Append when the procedure is performed on the left talus or calcaneus only. |
| -50 | Bilateral | Append when the identical procedure is performed on both the right and left talus/calcaneus in the same session; report on one line rather than -RT/-LT on two lines. |
| -25 | Significant, Separately Identifiable E/M | Append to an E/M service performed the same day if the physician evaluates the patient for a significant, separately identifiable problem beyond the routine pre-operative assessment for 28120. |
| -51 | Multiple Procedures | Append when 28120 is reported with other significant procedures performed in the same session, subject to multiple-procedure payment reduction rules. |
| -59 | Distinct Procedural Service | Append when a separately identifiable bone excision (e.g., 28122 on a different tarsal bone) is performed distinctly from 28120 in the same session. |
| -22 | Increased Procedural Services | Append when the excision is substantially more extensive than typical (e.g., unusually complex chronic osteomyelitis debridement), supported by operative documentation quantifying the added work. |
| -58 | Staged or Related Procedure During Postoperative Period | Append when a planned, staged bone procedure is performed during the 90-day global period related to the original excision. |
| -78 | Unplanned Return to the Operating/Procedure Room | Append when the patient returns to the OR for a complication of the original 28120 procedure (e.g., recurrent infection) within the global period. |
| -79 | Unrelated Procedure by the Same Physician During the Postoperative Period | Append when an unrelated procedure is performed on the same patient during the 90-day global period of 28120. |
🩺 Common ICD‑10‑CM Pairings
Primary Diagnosis Group — Osteomyelitis
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| M86.671 | Other chronic osteomyelitis, right ankle and foot | No | Most common indication for sequestrectomy/craterization when a chronic infected sequestrum of the talus or calcaneus is documented. |
| M86.672 | Other chronic osteomyelitis, left ankle and foot | No | Laterality must match the operative side and any -RT/-LT modifier on the CPT line. |
| M86.171 | Other acute osteomyelitis, right ankle and foot | No | Supports 28120 when the excision addresses an acute, non-hematogenous bone infection rather than a chronic process. |
| M86.172 | Other acute osteomyelitis, left ankle and foot | No | Chronicity documentation (acute vs. chronic) determines whether M86.1- or M86.6- applies; the parent M86 categories are not billable and must not be used. |
Secondary Group — Bossing / Bone Hypertrophy
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| M89.371 | Hypertrophy of bone, right ankle and foot | No | Supports 28120 when the indication is a symptomatic bony prominence (bossing) such as a posterior calcaneal exostosis rather than infection. |
| M89.372 | Hypertrophy of bone, left ankle and foot | No | Pair with modifier -LT to match laterality; document the specific bone (talus vs. calcaneus) in the operative note. |
Etiology / Complication
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| E11.621 | Type 2 diabetes mellitus with foot ulcer | Yes | Report as an additional diagnosis when diabetic foot ulceration is the underlying cause of osteomyelitis necessitating the excision; sequence per ICD-10-CM guidelines with the ulcer code. |
| I73.9 | Peripheral vascular disease, unspecified | No | Document when compromised peripheral circulation is a contributing comorbidity affecting surgical planning and postoperative healing risk. |
Coding Specificity Reminder
Never report the unspecified parent categories M86 or M89 alone — ICD-10-CM 2026 requires full specification of laterality (right/left) and chronicity (acute/chronic) for these code families, and the truncated parent codes are not valid for claim submission. Always confirm whether the operative indication is infectious (osteomyelitis, M86 family) or purely structural (bossing/exostosis, M89.3- family), since this distinction also supports medical necessity review. When both an infection and a diabetic etiology coexist, sequence the diabetes combination code per the physician’s documented cause-and-effect relationship. Query the surgeon if the operative note documents “bossing” or “prominence” without specifying whether osteomyelitis is also present, since this changes the diagnosis code family entirely.
🏥 MS‑DRG Considerations
CPT 28120 is most frequently performed in an outpatient hospital or ASC setting and therefore typically does not generate an inpatient MS-DRG. When performed during an inpatient admission — for example, as part of treatment for severe diabetic foot osteomyelitis requiring hospitalization — the procedure groups under MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue) to an “Other Musculoskeletal System and Connective Tissue O.R. Procedures” MS-DRG. Final DRG assignment (with or without major complication/comorbidity) depends on the presence of documented complications such as sepsis, extensive diabetic complications, or peripheral vascular disease. Coders should ensure that any inpatient stay documentation supports the severity level driving DRG assignment, since osteomyelitis with associated comorbidities can significantly affect DRG weight.
🔧 ICD‑10‑PCS Equivalents
| PCS Code | Full Description | Modality |
|---|---|---|
| 0QBL0ZZ | Excision of Right Tarsal, Open Approach | Open |
| 0QBM0ZZ | Excision of Left Tarsal, Open Approach | Open |
| 0QBL3ZZ | Excision of Right Tarsal, Percutaneous Approach | Percutaneous |
| 0QBM3ZZ | Excision of Left Tarsal, Percutaneous Approach | Percutaneous |
PCS Character Analysis
| Position | Character | Value | Definition |
|---|---|---|---|
| 1 | Section | 0 | Medical and Surgical section, covering the vast majority of open and percutaneous procedures reported for inpatient encounters. |
| 2 | Body System | Q | Lower Bones — the ICD-10-PCS body system encompassing the pelvic, femoral, tibial, fibular, tarsal, metatarsal, and toe phalanx bones. |
| 3 | Root Operation | B | Excision — cutting out or off, without replacement, a portion of a body part, matching the “partial excision” concept of CPT 28120. |
| 4 | Body Part | L or M | Tarsal, Right (L) or Tarsal, Left (M) — ICD-10-PCS groups the talus and calcaneus together with the other five tarsal bones under a single “Tarsal” body part value. |
| 5 | Approach | 0 or 3 | Open (0) for a direct surgical incision, or Percutaneous (3) if performed through a needle/small puncture instrumentation approach. |
| 6 | Device | Z | No Device — no implant, graft, or other device is left in place as part of this excision procedure. |
| 7 | Qualifier | Z | No Qualifier — used when the excision is therapeutic rather than purely diagnostic (a diagnostic-only excision would use qualifier X instead). |
Root Operation Comparison
- Excision (B) removes only a portion of the body part, consistent with the “partial” nature of CPT 28120, whereas Resection (T) would apply only if the entire tarsal bone were removed.
- ICD-10-PCS does not distinguish talus from calcaneus; both map to the single “Tarsal” body part value, unlike CPT which separately names talus/calcaneus (28120) versus other tarsal/metatarsal bones (28122).
- If a device (e.g., bone graft substitute) were implanted to fill the resulting defect, the PCS code would shift to root operation Supplement (U) or Replacement (R) rather than Excision (B).
📝 Coding Examples
Example 1
Clinical Scenario: A 58-year-old male with type 2 diabetes presents with a chronic draining sinus over the right heel. Imaging and prior culture confirm chronic osteomyelitis of the right calcaneus. The surgeon performs an open sequestrectomy, removing a necrotic bone fragment and debriding the surrounding infected bone bed. A bone culture and pathology specimen are sent intraoperatively. The wound is irrigated and closed primarily over a drain. The patient is placed in a non-weight-bearing boot postoperatively.
| Field | Code | Rationale |
|---|---|---|
| CPT | 28120-RT | Sequestrectomy of a discrete necrotic bone fragment from the calcaneus matches the partial-excision technique described by 28120; -RT indicates the right-sided procedure. |
| PDx | M86.671 | Chronic osteomyelitis of the right ankle and foot is the fully specified, billable diagnosis supporting the excision. |
Note
Because the patient has underlying diabetes, E11.621 should also be reported if a diabetic foot ulcer contributed to the infection, with sequencing per the physician’s documented causal relationship.
Example 2
Clinical Scenario: A 34-year-old runner presents with a painful posterior-superior calcaneal prominence (Haglund’s deformity) refractory to six months of conservative therapy including heel lifts and physical therapy. Surgery includes a retrocalcaneal bursectomy followed by diaphysectomy of the prominent posterior calcaneal bone. No infection is present; imaging confirms isolated bone hypertrophy.
| Field | Code | Rationale |
|---|---|---|
| CPT 1 | 28119-LT | If a discrete spur (rather than broader prominence) were excised with plantar fascial release, 28119 would apply instead; documented here only for comparison. |
| CPT 2 | 28120-LT | Diaphysectomy of the posterior calcaneal prominence for symptomatic bossing matches 28120’s “bossing” indication, distinct from the isolated-spur scope of 28119. |
| PDx | M89.372 | Hypertrophy of bone, left ankle and foot, is the specific ICD-10-CM code for symptomatic calcaneal bossing without infection. |
Warning
Do not also report 28119 for the same operative session unless a clearly separate, distinct calcaneal spur (with plantar fascial release) is documented apart from the diaphysectomy — reporting both without distinct documentation risks an unbundling denial.
Example 3
Clinical Scenario: A 45-year-old female with peripheral vascular disease develops acute osteomyelitis of the left talus following an open ankle fracture repaired three months earlier. The orthopedic surgeon performs an open craterization of the infected talar bone, removing the infected cortical shell down to bleeding, healthy bone, followed by local antibiotic bead placement (reported separately).
| Field | Code | Rationale |
|---|---|---|
| CPT | 28120-LT | Craterization of the infected talus for acute osteomyelitis is the exact technique and anatomic site described by 28120. |
| PDx | M86.172 | Acute osteomyelitis, left ankle and foot, correctly reflects the acute (rather than chronic) infection process and left-sided laterality. |
Global period reminder
All post-operative wound checks, suture removal, and dressing changes related to this excision within 90 days are bundled into the global surgical package and are not separately billable unless a new, unrelated diagnosis or a return to the OR occurs.
⚠️ Common Coding Pitfalls
- Reporting 28120 when the entire calcaneus is removed: complete or near-complete calcanectomy should be reported with the more extensive 28118 ostectomy code, not the partial-excision code 28120.
- Confusing 28120 with 28119: 28119 is reserved specifically for isolated calcaneal spur excision (with or without plantar fascial release), while 28120 covers broader craterization, sequestrectomy, or diaphysectomy for osteomyelitis or bossing.
- Using unspecified or parent ICD-10-CM codes: the M86 and M89 parent categories are not billable in 2026 and must be reported with full laterality and chronicity specificity (e.g., M86.671, M89.372).
- Unbundling routine post-operative wound care: dressing changes, suture removal, and uncomplicated wound checks within the 90-day global period are bundled and should not be separately billed.
- Missing laterality modifiers: omitting -RT, -LT, or -50 on a unilateral or bilateral claim can trigger payer requests for additional documentation or claim rejection.
- Failing to distinguish infectious versus structural indications: documentation that only states “bossing” or “prominence” without addressing infection status can lead to an ICD-10-CM code family mismatch (M86 vs. M89.3-), which may affect medical necessity review.
Sources: ¹ American Medical Association, CPT 2026 Professional Edition — Surgery: Musculoskeletal System, Foot and Toes section. ² CMS National Physician Fee Schedule Relative Value File, PPRRVU2026. ³ CMS Medicare Coverage Database (MCD) — Jurisdiction LCD/NCD search, verified no CPT 28120-specific NCD/LCD as of 2026. ⁴ ICD-10-CM 2026 Tabular List, Chapter 13 (M86, M89 code families). ⁵ ICD-10-PCS 2026 Tables, Body System 0Q (Lower Bones).
Sources listed above correspond to superscript citations throughout this note. Verify all Medicare payment figures against your current CMS PFS Lookup tool and applicable MAC LCD prior to claim submission. Please use the latest AAPC/AHIMA Coding Books to verify each code within this note.