Deep incision through the bone cortex of the humerus or elbow region, typically performed to drain infection or decompress a bone abscess such as osteomyelitis.

Verified May 8, 2026 · 6 sources ↓

Medicare: $495.34
Work RVU: 6.22
Global, days: 90
Region: Elbow

Drawn from CMSEmednyAAPCCgsmedicareFaculty

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Operative note must explicitly document opening of the bone cortex — not just soft-tissue dissection.
Pre-operative imaging (X-ray, MRI, or bone scan) confirming intraosseous pathology such as osteomyelitis or bone abscess.
Anatomic location specified as humerus or elbow region.
ICD-10 diagnosis aligned to osteomyelitis (M86 series) or bone abscess — soft-tissue infection codes alone will not support cortical entry.
Wound culture or intraoperative specimen documentation if infection is the indication.
Post-op plan including antibiotic therapy or infectious disease co-management, which substantiates medical necessity.

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 50 Bilateral procedure 51 Multiple procedures 52 Reduced services 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 23935 covers a deep surgical incision that penetrates the bone cortex of the humerus or elbow — not just soft tissue. The classic indication is osteomyelitis or a localized bone abscess requiring cortical decompression and drainage. This is a distinct, more invasive procedure than 23930 (deep soft-tissue abscess or hematoma I&D) or 23931 (bursa I&D); the cortical opening is the defining element.

The 90-day global period means all routine post-op management through day 90 is bundled. If the patient returns within that window for a separate, unrelated procedure, append modifier 79. An unplanned return to the OR for a complication directly related to the original surgery uses modifier 78. New E/M visits for unrelated conditions during the global need modifier 24.

Documentation must support cortical involvement — imaging (plain film, MRI, or bone scan) confirming intraosseous pathology is expected at audit. Operative notes that describe only soft-tissue dissection without explicit cortical entry will not support this code; use 23930 or 23931 instead. ICD-10 diagnosis codes should reflect osteomyelitis (M86 series) or bone abscess to align with the procedure.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (6.22) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (14.83) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	6.22
Practice expense RVU	7.31
Malpractice RVU	1.3
Total RVU	14.83
Medicare national rate	$495.34
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	$495.34
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 23935 get rejected.

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

Operative note lacks documentation of cortical entry — payer downcodes to 23930 or 23931.
Diagnosis code reflects soft-tissue abscess or cellulitis only, with no intraosseous pathology to justify bone cortex incision.
Missing or absent pre-operative imaging to confirm osteomyelitis or bone abscess.
Billing 23935 same-day as 23930 or 23931 without a distinct anatomic site or supporting modifier, triggering NCCI bundling edits.
Global period violation — post-op E/M or related procedure billed without required modifier 24, 78, or 79.

Frequently asked questions

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

01What separates 23935 from 23930?

23930 covers I&D of a deep soft-tissue abscess or hematoma in the upper arm or elbow. 23935 requires surgical entry through the bone cortex. If you didn't open the cortex, 23930 or 23931 is the correct code.

02Can 23935 and 23930 be billed together on the same date?

Only if they address genuinely distinct anatomic sites — for example, a soft-tissue abscess treated separately from a cortical decompression at a different location. You'll need modifier 59 or XS and documentation supporting both separate lesions.

03What ICD-10 codes support 23935?

Osteomyelitis codes in the M86 series (acute, subacute, chronic hematogenous, or other osteomyelitis of the humerus) are the primary drivers. A bone abscess without osteomyelitis may also qualify. Soft-tissue infection codes alone (L02, L03) will not support a cortical incision.

04Does the 90-day global include post-op antibiotic management visits?

Routine post-op visits are bundled in the 90-day global. However, if an infectious disease specialist (not the operating surgeon) manages the antibiotic regimen, that physician bills separately under their own provider number. The operating surgeon's routine follow-up is global.

05When is modifier 22 appropriate for 23935?

Use modifier 22 when the procedure is substantially more work than typical — for example, extensive chronic osteomyelitis requiring prolonged debridement, significant scar tissue, or multiple cortical windows. The operative note must describe the specific factors that increased complexity and time.

06Is 23935 performed bilaterally?

Bilateral osteomyelitis of the humerus is rare but possible. If both arms are treated at the same session, append modifier 50 and document bilateral intraosseous pathology. Each site needs supporting imaging and its own indication in the operative note.

07What is the site-of-service impact for 23935?

HOPD and ASC payments differ materially — see the Site of Service comparison on this page. Facility choice affects both the facility payment and the surgeon's professional fee (the physician fee schedule pays a lower work RVU in a facility setting than in a non-facility setting).

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira Scribe

Mira's AI scribe captures explicit cortical entry language from dictation — phrases like 'opened the bone cortex,' 'cortical window created,' or 'periosteum elevated and cortex drilled/incised' — and flags notes that describe only soft-tissue drainage without cortical penetration. This prevents the most common audit failure for 23935: an operative note that reads like a 23930 and gets downcoded on review.

See how Mira captures CPT 23935 documentation