Open repair of a nasomaxillary complex fracture requiring multiple open surgical approaches (LeFort II type).

Verified May 8, 2026 · 7 sources ↓

Medicare: $939.23
Total RVUs: 28.12
Global, days: 90
Region: Other

Drawn from CMSAAPCFindacodeEmednyAAOS

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Explicitly name each open surgical approach used (e.g., coronal, subciliary, transoral); 'multiple approaches' without specifics is an audit flag.
Describe the fracture pattern and why multiple open approaches were necessary — single-approach adequacy must be ruled out in the note.
Document mechanism of injury and clinical findings confirming LeFort II-type nasomaxillary complex involvement.
If modifier 22 is appended, include a separate narrative quantifying the substantially increased operative time or complexity beyond the typical procedure.
Record fixation method used (plates, wires, screws) and any intraoperative imaging or fluoroscopy performed.
If assistant surgeon was present, document medical necessity for the assistant in the operative report.

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 57 Decision for surgery 58 Staged or related 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 21347 covers open treatment of a nasomaxillary complex (LeFort II-type) fracture when the repair demands multiple open approaches — distinguishing it from 21346, which covers open treatment with wiring or local fixation via a single approach. The nasomaxillary complex spans the nasal bones and maxilla, forming the structural bridge between the skull base and the occlusal plane. Injuries severe enough to require this code typically result from significant blunt force trauma and present with comminution, displacement, or involvement of multiple facial buttresses that cannot be addressed through a single access point.

This is a 90-day global procedure. All routine post-op care, splint management, and follow-up visits through day 90 are bundled. An E/M on the day of or day before surgery requires modifier 57 if that visit represents the decision for surgery. Any unrelated procedure performed by the same surgeon within the global window needs modifier 79; an unplanned return to the OR for a related complication requires modifier 78. If staged secondary reconstruction was planned from the outset and documented in the original operative note, use modifier 58 — it resets the global clock.

Code selection within this family is approach-driven. Use 21346 for open repair with wiring or local fixation via a standard single approach. Use 21347 only when multiple open approaches are required. If bone grafting is also performed, step up to 21348, which includes graft harvest. Misassignment between 21346 and 21347 is a common audit target — operative notes must explicitly name and describe each approach used.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	13.19
Practice expense RVU	13.01
Malpractice RVU	1.92
Total RVU	28.12
Medicare national rate	$939.23
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	$939.23
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI J8) Ambulatory surgical center (freestanding)	$3,873.89

Common denial reasons

The recurring reasons claims for CPT 21347 get rejected.

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

Upcoding from 21346 to 21347 when operative note describes only one open approach or does not explicitly enumerate multiple approaches.
Missing modifier 57 on a same-day or day-before E/M billed outside the global period for a 90-day major surgical procedure.
Modifier 22 appended without a supporting narrative explaining the additional work — payers routinely downcode or deny without documentation.
Unbundling 21348 procedures by billing 21347 plus a separate bone graft code when grafting was performed — graft harvest is included in 21348.
ICD-10 diagnosis code does not support LeFort II-type nasomaxillary involvement, causing a CPT-to-diagnosis mismatch denial.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01What separates 21347 from 21346?

Approach count. Use 21346 when open repair is accomplished through a single approach with wiring or local fixation. Use 21347 only when the repair requires multiple distinct open approaches. The operative note must name each approach — auditors will not infer it.

02When should I use 21348 instead of 21347?

If bone grafting was performed as part of the nasomaxillary repair, bill 21348, which includes graft harvest. Do not bill 21347 plus a separate graft code when grafting was done in the same operative session.

03Can I bill an E/M on the same day as 21347?

Only with modifier 57 if the visit represents the decision for surgery. Because 21347 carries a 90-day global, the day-before and day-of visits are bundled unless modifier 57 documents that the surgical decision was made at that encounter.

04Does modifier 50 apply to 21347?

Theoretically yes if bilateral structures are addressed, but true bilateral LeFort II nasomaxillary procedures are anatomically uncommon. If you're considering modifier 50, confirm your payer's policy — some require separate line items with LT/RT instead.

05What ICD-10 codes support 21347?

Look to S02 fracture codes covering nasal bones and maxillary fractures with the appropriate laterality and encounter qualifiers (initial encounter uses the A suffix for open treatment). The diagnosis must reflect nasomaxillary complex involvement — a simple nasal bone fracture alone does not support this code.

06If the patient returns to the OR within the 90-day global for a related complication, what modifier applies?

Modifier 78 — unplanned return to the OR for a related procedure during the postoperative period. Do not use modifier 79 for related returns; 79 is reserved for unrelated procedures in the global window.

07Is an assistant surgeon payable for 21347?

Verify with the specific payer. If an assistant is medically necessary and allowed, append modifier 80 for an MD assistant or modifier AS for a PA or NP. Document the clinical reason an assistant was required in the operative note.

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 specific open approaches used (e.g., coronal, subciliary, gingivobuccal), the fracture pattern, fixation hardware applied, and the clinical rationale for requiring multiple access points rather than a single approach. That dictation prevents the most common denial for 21347: an operative note that says 'multiple approaches' without naming them, which auditors treat as unsupported upcoding from 21346.

See how Mira captures CPT 21347 documentation