Open surgical repair of a complicated malar (cheekbone) fracture — comminuted or involving cranial nerve foramina — including zygomatic arch and malar tripod, with bone grafting.

Verified May 8, 2026 · 6 sources ↓

Medicare: $1,138.64
Total RVUs: 34.09
Global, days: 90
Region: Other

Drawn from CMSAAPC

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 fracture pattern — comminution, involvement of cranial nerve foramina, zygomatic arch, and malar tripod — not just 'complex malar fracture'
Document all surgical approaches used by name; notes that say 'standard approach' invite audit flags
Graft type and harvest site must be documented; autograft harvest is bundled, but the harvest site and graft quantity should be in the note
Imaging (CT preferred) confirming fracture complexity should be referenced in the operative report or pre-op workup
ICD-10 diagnosis code must reflect the specific fracture complexity — comminuted, multi-fragment, or cranial nerve foramina involvement — to match the code selection
If modifier 22 is applied, the operative note must quantify the additional work: extra time, unusual anatomy, number of fragments, or proximity to critical structures

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 58 Staged or related 59 Distinct service 62 Co-surgeons 76 Repeat, same physician 77 Repeat, another physician 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 21366 covers open treatment of a complicated malar fracture — think comminuted fragments or fracture lines running through cranial nerve foramina — that also involves the zygomatic arch and malar tripod, performed with bone grafting including graft harvest. This is not a simple open reduction; the complexity threshold requires multiple surgical approaches and structural reconstruction, not just fixation. The graft component (autograft harvest included) is bundled into the code — don't separately bill a bone graft harvest code.

The 90-day global period governs post-op billing. Any unrelated procedure in that window needs modifier 79; a staged or planned return for a related procedure needs modifier 58. If a second surgeon assists in distinct portions of the reconstruction, modifier 62 applies. Modifier 22 is defensible when operative time or complexity significantly exceeds the norm — document the specific factors (severe comminution, proximity to cranial nerve foramina, number of approaches) in the operative note, not just on the claim.

This code carries ASC status indicator J8, meaning it was added to the ASC Covered Procedures List effective January 1, 2026. Site-of-service selection affects payment materially — see the Site of Service comparison table on this page. ICD-10 diagnosis coding must reflect the complexity: a simple malar fracture without involvement of the foramina or significant comminution does not support 21366 over lower-acuity malar fracture codes.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	18.14
Practice expense RVU	12.59
Malpractice RVU	3.36
Total RVU	34.09
Medicare national rate	$1,138.64
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	$1,138.64
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 21366 get rejected.

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

Diagnosis code reflects a non-complex malar fracture, creating a mismatch with the complexity requirements of 21366
Bone graft harvest billed separately when it is already bundled into 21366
Modifier 22 applied without supporting documentation of specific complexity factors in the operative note
Procedure billed in an outpatient facility setting prior to the code's addition to the ASC Covered Procedures List (effective January 1, 2026)
Post-op related procedure billed without modifier 58 during the 90-day global period

Frequently asked questions

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

01Is bone graft harvest separately billable with CPT 21366?

No. Graft harvest is bundled into 21366 — the code descriptor explicitly states 'includes obtaining graft.' Billing a separate harvest code will trigger an NCCI edit denial.

02What distinguishes 21366 from lower-acuity malar fracture codes?

21366 requires documented complexity: comminution, cranial nerve foramina involvement, or multi-structure involvement (zygomatic arch and malar tripod) requiring bone grafting. Straightforward open malar repairs without grafting fall under different codes in the 21360 family.

03Can 21366 be performed in an ASC under Medicare?

Yes, effective January 1, 2026. CMS added 21366 to the ASC Covered Procedures List with status indicator J8. Prior to that date, it was restricted to hospital outpatient settings under OPPS.

04When does modifier 22 apply for this procedure?

When the case required substantially more work than the typical 21366 — severe comminution, unexpected proximity to cranial nerve structures, extended operative time, or unusual patient anatomy. The operative note must document those specifics; 'difficult case' language alone won't support the modifier.

05What global period applies and how does it affect post-op billing?

21366 carries a 90-day global period. Routine post-op visits, dressings, and wound checks through day 90 are included. Unrelated procedures in that window need modifier 79. Planned staged procedures need modifier 58. Unplanned returns for a related complication need modifier 78.

06If two surgeons perform distinct portions of the reconstruction, how should billing be handled?

Both surgeons bill 21366 with modifier 62. Each must document their distinct contribution in a separate operative note or clearly delineated section of a shared note. Modifier 80 applies if one surgeon acts as assistant rather than a co-primary.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures fracture pattern specifics from dictation — comminution, cranial nerve foramina involvement, number of surgical approaches, graft harvest site and type, and zygomatic arch or malar tripod involvement. That detail lands directly in the operative note, preventing the diagnosis-code mismatch and missing-complexity documentation that drive 21366 denials.

See how Mira captures CPT 21366 documentation