Surgical removal of a sequestrum — a segment of necrotic bone — from the clavicle, typically performed to treat osteomyelitis or a bone abscess.

Verified May 8, 2026 · 6 sources ↓

Medicare: $540.76
Total RVUs: 16.19
Global, days: 90
Region: Shoulder

Drawn from CMSEmednyProvidersAAPCAAOS

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Preoperative imaging (X-ray, MRI, or CT) confirming sequestrum or bone abscess of the clavicle
Operative note identifying the necrotic bone fragment, extent of debridement, and confirmation of viable bone margins at the resection edges
Intraoperative culture and pathology specimen documentation linking the excised tissue to infection or abscess
Diagnosis code tied to osteomyelitis or bone abscess (ICD-10 M86.x1x or similar) — must match the surgical indication
Documentation distinguishing this procedure from partial claviculectomy (23120) or craterization/saucerization (23180) if those codes are under consideration
Prior authorization approval on file when required by payer (required by FEP and many commercial plans)

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 52 Reduced services 57 Decision for surgery 58 Staged or related 59 Distinct service 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 6 cited references ↓

CPT 23170 describes open sequestrectomy of the clavicle, performed to excise devitalized bone (sequestrum) that has separated from viable tissue as a result of osteomyelitis or a bone abscess. The procedure involves exposing the infected clavicular segment, debriding necrotic bone until bleeding, viable margins are reached, and irrigating the wound. Cultures are routinely obtained intraoperatively to guide postoperative antibiotic therapy.

This code carries a 90-day global period. All routine follow-up visits, wound checks, and dressing changes within that window are bundled — bill separately only for services clearly unrelated to the infection or the surgical site, appending modifier 24 or 25 as appropriate. Prior authorization is required by many payers, including Federal Employee Program plans (per Highmark FEP guidance); confirm requirements before scheduling.

Do not confuse 23170 with adjacent clavicle excision codes. Partial claviculectomy (23120) removes a structural segment of bone; 23170 targets only the infected, necrotic fragment. If the surgeon also performs partial excision with craterization or saucerization for osteomyelitis (beyond simple sequestrum removal), consider 23180 instead. Document the distinction explicitly — auditors look for operative notes that justify code selection at the procedure-description level.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	7.03
Practice expense RVU	7.68
Malpractice RVU	1.48
Total RVU	16.19
Medicare national rate	$540.76
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	$540.76
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI J8) Ambulatory surgical center (freestanding)	$2,310.74

Common denial reasons

The recurring reasons claims for CPT 23170 get rejected.

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

Missing or inadequate prior authorization — many payers, including FEP plans, require pre-auth for shoulder excision procedures
ICD-10 diagnosis code does not specify osteomyelitis or bone abscess, causing a medical necessity mismatch with the surgical indication
Operative note describes only debridement without explicitly identifying and excising a discrete necrotic bone sequestrum, supporting a lower-level code instead
Upcoding concern when 23170 is billed but the note better supports partial claviculectomy (23120) or limited craterization (23180)
Global period billing errors — post-op wound care or infection follow-up billed without modifier 24, triggering automatic bundling denials

Frequently asked questions

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

01What is the difference between CPT 23170 and CPT 23180?

23170 is sequestrectomy — removal of a discrete necrotic bone fragment (sequestrum) from the clavicle. 23180 is partial excision with craterization, saucerization, or diaphysectomy for osteomyelitis of the clavicle. If the surgeon excavates a cavity in viable bone beyond simply extracting a loose sequestrum, 23180 is the more accurate code. The operative note must support whichever code is billed.

02Does CPT 23170 require prior authorization?

Yes for many payers. Federal Employee Program (FEP) plans explicitly list 23170 as requiring prior authorization. Verify requirements with each payer before scheduling — denials for missing auth are common and difficult to overturn retroactively.

03Can 23170 and 23120 (partial claviculectomy) be billed together on the same day?

Only if the operative note documents two truly distinct and separately necessary procedures on different parts of the clavicle. If the partial claviculectomy was performed as part of the infected field, it is bundled. Append modifier 59 to the column-2 code only when the procedures are clinically distinct and documentation supports separate reporting.

04What ICD-10 codes support medical necessity for 23170?

Osteomyelitis codes (ICD-10 M86 series — acute, subacute, or chronic) and bone abscess of the clavicle are the primary supporting diagnoses. Be as specific as possible: payers flag claims where the diagnosis is coded to an unspecified site when the clavicle is clearly identified in the operative note.

05How does the 90-day global period affect billing for osteomyelitis follow-up after 23170?

Routine wound checks, dressing changes, and infection monitoring related to the sequestrectomy are bundled through day 90. If the patient develops a new or unrelated condition requiring an E/M visit in that window, append modifier 24. If a separate procedure is required for an unrelated problem, use modifier 79. A return to the OR for re-debridement of the same infection site uses modifier 78.

06Is 23170 performed arthroscopically?

No. 23170 is an open procedure. There is no arthroscopic equivalent for clavicular sequestrectomy in the current CPT code set. Billing an arthroscopy code for this procedure would be a misrepresentation of the surgical approach.

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 surgeon's dictation of the sequestrum location on the clavicle, size and extent of necrotic bone removed, status of surrounding viable bone margins, intraoperative culture collection, and wound management technique. That detail prevents the most common audit flag for 23170: an operative note that documents bone debridement generically without distinguishing an isolated sequestrum excision from a broader craterization procedure.

See how Mira captures CPT 23170 documentation