Open surgical repair of a depressed fracture of the frontal sinus, accessed through a direct incision to reduce and stabilize the fractured bone segments.

Verified May 8, 2026 · 7 sources ↓

Medicare: $974.64
Total RVUs: 29.18
Global, days: 90
Region: Other

Drawn from CMSAAPCNIHMdclarityCgsmedicare

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Mechanism of injury documented (blunt force, crush trauma) with onset date
Imaging findings confirming depressed fracture of the frontal sinus specifically
Operative note identifies surgical approach by name and confirms open access to fracture site
Description of fracture reduction technique and stabilization method used
If modifier 22 appended: operative note must quantify increased time, complexity, or difficulty beyond typical procedure
If modifier 62 used: each surgeon's distinct operative contribution documented separately

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 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

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 21343 covers open treatment of a depressed frontal sinus fracture — typically the result of blunt force or crush trauma below the brow ridge. The surgeon accesses the fracture through an incision, reduces the depressed bone segment, and stabilizes the repair. This is distinct from closed or percutaneous approaches to adjacent facial fractures (e.g., 21338–21340 for nasoethmoid fractures), so documentation must clearly establish which structure was treated and which operative technique was used.

The code carries a 90-day global period. All routine follow-up, wound checks, and dressing changes through day 90 are bundled. If you're managing an unrelated condition or treating a new injury during that window, append modifier 79. An unplanned return to the OR for a complication related to the original repair requires modifier 78.

When two surgeons share operative responsibility for distinct portions of a complex repair — common in cases with concurrent orbital or cranial involvement — both surgeons bill 21343 with modifier 62. If the complexity of the case substantially exceeds the typical procedure (e.g., extensive comminution, scarring, prior surgery), modifier 22 is appropriate, but the operative note must quantify the additional work, not just note difficulty.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	13.96
Practice expense RVU	13.17
Malpractice RVU	2.05
Total RVU	29.18
Medicare national rate	$974.64
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	$974.64
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,077.94

Common denial reasons

The recurring reasons claims for CPT 21343 get rejected.

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

Wrong anatomic site coded — operative note describes nasoethmoid or orbital fracture, not frontal sinus
Approach not documented as open — payer defaults to closed treatment code
Modifier 22 appended without operative note language supporting substantially increased work
Global period billing conflict — follow-up visit billed without modifier 24 or 79 during the 90-day window
ICD-10 diagnosis code does not specify frontal sinus or does not lateralize when required by payer

Frequently asked questions

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

01How does 21343 differ from 21338 or 21340 for nasoethmoid fractures?

21343 is specific to the frontal sinus. Codes 21338–21340 cover nasoethmoid complex fractures. If both structures are treated in the same session, bill each code separately with modifier 59 to distinguish the distinct anatomic sites.

02Can 21343 be billed with orbital fracture repair codes in the same session?

Yes, if the frontal sinus and orbital fractures are treated as distinct procedures through separate operative steps. Append modifier 59 or 51 as appropriate and ensure the operative note documents each repair independently.

03When is modifier 62 appropriate for this code?

Use modifier 62 when two surgeons — often a craniofacial or plastic surgeon paired with a neurosurgeon — each perform distinct, necessary portions of the open frontal sinus repair. Both surgeons bill 21343-62 with separate operative notes describing their individual contributions.

04What ICD-10 codes typically pair with 21343?

S02.19XA (fracture of other specified skull and facial bones, initial encounter) is commonly used. Some payers require more specific laterality or fracture type coding, so verify the diagnosis code specificity against your MAC's LCD and payer contract.

05Is 21343 performed in an ASC, or is this typically a hospital case?

Most depressed frontal sinus repairs are performed in a hospital outpatient or inpatient setting given the proximity to the anterior cranial fossa and risk of dural involvement. ASC payment is available under the fee schedule, but complex cases with intracranial extension are generally not appropriate for ASC.

06What happens if the patient requires a second return to the OR during the 90-day global?

If the return is for a complication directly related to the frontal sinus repair, bill 21343 again with modifier 78. If the return addresses an unrelated condition or injury, use modifier 79. Never bill a global-period return without one of these modifiers — it will deny as a duplicate.

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 mechanism of injury, specific fracture location (frontal sinus, not nasoethmoid or orbital rim), surgical approach, reduction method, and stabilization technique directly from dictation. This prevents the most common audit flag for 21343: an operative note that describes the approach generically or documents an adjacent structure rather than the frontal sinus, which triggers downcoding or site-of-service mismatch denials.

See how Mira captures CPT 21343 documentation