Surgical · Other

Reconstruction of the zygomatic arch and glenoid fossa using bone and cartilage autografts harvested from the patient during the same operative session.

Verified May 8, 2026 · 5 sources ↓

Medicare: $1,221.14
Total RVUs: 36.56
Global, days: 90
Region: Other

Drawn from CMSAaomsAaoAAPC

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Preoperative imaging (CT or panoramic radiograph) confirming structural deficiency of the zygomatic arch and/or glenoid fossa
Operative note specifying the zygomatic arch and glenoid fossa as the reconstructed structures — generic 'craniofacial reconstruction' language is insufficient
Documentation of autograft harvest site, graft type (bone, cartilage, or both), and technique used to obtain the graft
Diagnosis supporting medical necessity: trauma sequela, post-ablative defect, or documented congenital/acquired deformity causing functional impairment
If billing same-day E/M, separate documentation justifying a distinct evaluation beyond the pre-surgical assessment (modifier 57 for decision to operate, modifier 25 if a separately identifiable E/M on same day)

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 52 Reduced services 57 Decision for surgery 58 Staged or related 62 Co-surgeons 74 Discontinued post-anesthesia 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 21255 covers surgical reconstruction of the zygomatic arch — the bony ridge running along the side of the skull beneath the orbit — and the glenoid fossa, the concave articular surface at the root of that arch that articulates with the mandibular condyle. The procedure uses autogenous bone and cartilage grafts; graft harvest is included in the code and not separately billable. Indications include post-traumatic deformity, ablative oncologic defects, and congenital craniofacial anomalies where the native architecture of the temporomandibular articulation is structurally compromised.

This is a 90-day global code with substantial work RVU. Medicare and most commercial payers classify it as a reconstructive procedure — not cosmetic — but coverage requires documented functional impairment or a qualifying diagnosis (trauma sequela, malignancy-related defect, or recognized craniofacial deformity). Palmetto GBA and similar MACs restrict facial/maxillofacial reconstruction codes to diagnoses tied to trauma or ablative surgery; submitting without a qualifying ICD-10 is the fastest path to denial.

Don't confuse 21255 with adjacent codes: 21247 reconstructs the mandibular condyle with autografts, while 21241–21243 address TMJ arthroplasty with or without prosthetic components. When the condyle and the zygomatic arch/glenoid fossa both require reconstruction in the same session, payer policy on separate reporting varies — document distinct anatomic sites and review applicable NCCI edits before billing both.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	18
Practice expense RVU	15.95
Malpractice RVU	2.61
Total RVU	36.56
Medicare national rate	$1,221.14
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	$1,221.14
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI J8) Ambulatory surgical center (freestanding)	$3,833.49

Common denial reasons

The recurring reasons claims for CPT 21255 get rejected.

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

Cosmetic vs. reconstructive classification — payer denies without a qualifying diagnosis linking the defect to trauma or ablative surgery
Operative note documents only 'lower jaw reconstruction' without naming the zygomatic arch and glenoid fossa, causing a code-to-documentation mismatch on audit
Graft harvest billed separately (e.g., with a distinct harvest code) when harvest is already bundled into 21255
Missing prior authorization — 21255 is a high-RVU craniofacial code that most commercial payers require pre-auth for

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01Is graft harvest separately billable when performing 21255?

No. Obtaining the autogenous bone and cartilage grafts is bundled into 21255. Billing a separate harvest code for the same session will be denied as unbundling.

02How does 21255 differ from 21247?

21247 reconstructs the mandibular condyle with bone and cartilage autografts. 21255 reconstructs the zygomatic arch and glenoid fossa. They address different anatomic structures; if both are genuinely reconstructed in one session, document distinct sites and verify NCCI edit status before billing together.

03What ICD-10 diagnoses support medical necessity for 21255?

Payer LCDs (e.g., Palmetto GBA) restrict coverage to defects resulting from trauma or ablative surgery. Qualifying diagnoses include post-traumatic zygomatic deformity sequelae, post-oncologic resection defects, and documented congenital craniofacial deformities causing functional impairment. Cosmetic indications are excluded.

04Does the 90-day global period affect billing for TMJ-related follow-up?

Yes. Routine post-op visits, splint adjustments, and wound checks within 90 days are included in the global. Unrelated TMJ management (e.g., treating a separate dislocation unrelated to the reconstruction) needs modifier 79. A new, distinct complication requiring a return to the OR uses modifier 78 if related to the original procedure.

05Is prior authorization required for 21255?

Most commercial payers require it given the code's high facility payment. Confirm with each payer before scheduling. Medicare does not require prior auth for most surgical codes, but MAC coverage criteria still apply and will drive post-payment review.

06Can 21255 be billed with modifier 50 for bilateral procedures?

The zygomatic arch and glenoid fossa are bilateral structures. If reconstruction is performed on both sides in the same session, modifier 50 may apply, but verify with the specific payer — some require LT/RT modifiers on separate line items instead of a single line with modifier 50.

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 reconstructed structures by name (zygomatic arch, glenoid fossa), the autograft harvest site and tissue type, the indication (trauma, oncologic resection, congenital deformity), and the functional deficit documented preoperatively. That specificity prevents the operative note from reading like a generic craniofacial procedure, which is the primary trigger for cosmetic-vs.-reconstructive denials and post-payment audit flags on this code.

See how Mira captures CPT 21255 documentation