Surgical · Other

Complete subperiosteal implant reconstruction of the mandible or maxilla, placing a custom implant on top of the jawbone beneath the periosteum to restore jaw structure and function.

Verified May 8, 2026 · 6 sources ↓

Medicare: $767.89
Total RVUs: 22.99
Global, days: 90
Region: Other

Drawn from CMSEmednyFindacodeGenhealthAAOS

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 specify complete (not partial) coverage of the mandible or maxilla and confirm subperiosteal implant placement beneath the periosteum
Pre-operative imaging (CT or CBCT) demonstrating extent of bone loss or deformity and confirming implant design rationale
ICD-10 diagnosis reflecting the underlying etiology — atrophy, post-resection defect, trauma, or congenital anomaly — with clinical narrative support
Implant specifications documented: material, manufacturer, custom vs. stock, and confirmation of complete jaw coverage
Prior authorization documentation and payer-required clinical justification where applicable (Humana, HealthFirst, and regional plans commonly require this)
Evidence that less-invasive alternatives (conventional dentures, partial bone grafting) were considered or attempted and deemed insufficient

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 52 Reduced services 59 Distinct service 62 Co-surgeons 80 Assistant surgeon AS PA/NP/CNS assistant

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 21246 covers complete reconstruction of the mandible or maxilla using a subperiosteal implant — a custom framework seated directly on the bone surface, under the periosteum, spanning the entire jaw rather than a partial segment. This distinguishes it from 21245, which covers only a partial subperiosteal reconstruction. The procedure addresses severe jawbone atrophy, post-resection defects, trauma sequelae, or congenital deformity where the remaining bone cannot support conventional implants or dentures without structural augmentation.

The implant is typically fabricated from titanium or a biocompatible alloy and custom-fitted to the patient's residual ridge. The surgeon elevates the periosteum, seats the framework on the bone, and secures it before closure. The 90-day global period covers all routine post-operative management through day 90, including follow-up visits for wound checks and implant evaluation. Any unrelated E/M service during the global window requires modifier 24; a new problem requiring a separate decision for surgery needs modifier 25 if billed on the surgical date.

Primary indication coding must reflect the underlying pathology — atrophy, tumor resection defect, trauma, or congenital anomaly — not simply 'jaw reconstruction.' Payer medical necessity review is aggressive for this code; Humana, HealthFirst, and several regional plans have explicit orthognathic and reconstructive surgery policies that require prior authorization and documented failure of less-invasive alternatives.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	12.6
Practice expense RVU	8.56
Malpractice RVU	1.83
Total RVU	22.99
Medicare national rate	$767.89
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	$767.89
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI J8) Ambulatory surgical center (freestanding)	$5,000.74

Common denial reasons

The recurring reasons claims for CPT 21246 get rejected.

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

Missing or insufficient prior authorization — multiple major payers list this procedure under orthognathic or reconstructive surgery policies requiring pre-approval
Diagnosis coded as cosmetic or unspecified rather than a covered reconstructive indication such as tumor resection sequela, trauma, or documented severe atrophy
Billing 21246 when only a partial segment was reconstructed — partial procedures map to 21245 and auditors will flag the mismatch against the operative note
Global period billing conflict — routine post-op visits billed without modifier 24 or 25 during the 90-day window trigger automatic denials
Incomplete operative documentation lacking explicit confirmation of 'complete' jaw coverage, causing medical necessity reviewers to downcode to 21245

Frequently asked questions

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

01What is the difference between CPT 21245 and 21246?

21245 is a partial subperiosteal implant reconstruction; 21246 is the complete version covering the entire mandible or maxilla. The operative note must explicitly state complete coverage — auditors will downcode to 21245 if documentation is ambiguous about extent.

02Does CPT 21246 require prior authorization?

For most commercial payers, yes. Humana, HealthFirst, and several regional plans have explicit reconstructive or orthognathic surgery medical policies that require prior authorization and documentation of reconstructive (non-cosmetic) indication before the procedure.

03What is the global period for 21246 and what does it include?

The global period is 90 days. It covers the surgery, the day-before pre-op visit, and all routine post-operative care through day 90. Unrelated E/M visits during that window need modifier 24; a separate E/M on the day of surgery for a new problem needs modifier 25.

04Can 21246 be billed with a bone grafting code on the same day?

Potentially, but check NCCI PTP edits before billing a grafting code alongside 21246. If the graft is a distinct, separately documented procedure not integral to the subperiosteal implant placement, modifier 59 may apply — but confirm there is no bundling edit that makes the graft component inclusive to the primary reconstruction.

05Which ICD-10 codes typically support medical necessity for 21246?

Covered indications include acquired jaw deformity from tumor resection (post-procedural sequelae codes), traumatic bone loss, severe ridge atrophy, and documented congenital anomalies. Cosmetic diagnoses or unspecified jaw disorder codes will trigger denial across virtually all payers.

06Is co-surgeon billing (modifier 62) appropriate for 21246?

It can be, particularly when an oral and maxillofacial surgeon and a reconstructive surgeon co-manage the case with distinct, documented roles. Both surgeons bill 21246 with modifier 62, and each operative note must reflect that surgeon's specific intraoperative contribution.

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 implant type, material, and whether coverage was complete versus partial, the specific jaw (mandible vs. maxilla), periosteal elevation technique, and the underlying clinical indication driving reconstruction. That detail prevents the two most common audit flags: downcoding to 21245 for incomplete documentation of full jaw coverage, and denial for unspecified or cosmetic diagnosis coding.

See how Mira captures CPT 21246 documentation