Surgical removal of the entire upper extremity including the scapula and clavicle — the forequarter amputation — typically performed for bone or soft tissue sarcomas that cannot be managed by limb-salvage surgery.

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

• Pathology or imaging confirming the diagnosis driving amputation (e.g., sarcoma staging MRI/CT, biopsy report) — payers routinely request this for prior authorization and post-payment audit.
• Operative note specifying the exact anatomical structures removed: arm, scapula, clavicle, and any chest wall components; vague language such as 'forequarter amputation performed' without structural detail is an audit flag.
• Documentation that limb salvage was considered and was not oncologically, traumatically, or clinically feasible — required for medical necessity support with most payers.
• Level of major vascular and neurologic structures ligated or divided (subclavian vessels, brachial plexus), required to support the complexity and any modifier 22 claim.
• Laterality documented explicitly (right vs. left shoulder) in both the operative note and the claim to support LT/RT modifier assignment.
• Pre-operative multidisciplinary consultation notes (oncology, anesthesia, physical therapy) when available, as these support medical necessity for commercial payer review.
• Post-operative pathology report confirming margins when the indication is malignancy — absence of this report is a common audit gap for oncologic amputation cases.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

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

Common denial reasons

The recurring reasons claims for CPT 23900 get rejected.

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

• Medical necessity not established — payer requires documentation that limb-salvage options were evaluated and deemed inappropriate before approving an ablative procedure of this magnitude.
• Missing or insufficient prior authorization — given the high facility payment, most commercial payers and many Medicare Advantage plans require pre-authorization; claims submitted without it are denied outright.
• Laterality modifier absent or incorrect — submitting without LT or RT triggers an edit; submitting the wrong side relative to operative documentation triggers a post-payment audit and recoupment.
• Operative note does not support the code — notes that describe a shoulder disarticulation (23920) rather than full forequarter removal with clavicle and scapula will prompt a downcode to 23920.
• Global period billing conflict — services billed separately during the 90-day post-op window without the correct modifier (24, 78, or 79) are automatically bundled and denied.