Open treatment of an orbital floor blowout fracture via periorbital approach, with placement of an alloplastic or other implant to reconstruct the orbital floor.

Verified May 8, 2026 · 7 sources ↓

Medicare: $708.43
Work RVU: 10.95
Global, days: 90
Region: Other

Drawn from CMSAAPCHopkinsmedicineEmednyFindacode

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Operative note must name the specific surgical approach — 'periorbital approach' — not generic language like 'standard approach'.
Document the implant by type, material, and manufacturer; attach the implant sticker or invoice to the operative record.
Imaging (CT orbit) confirming orbital floor blowout fracture must be referenced, with findings correlating to the operative indication.
Operative note must describe the fracture site exposure, reduction maneuver, implant sizing, and final positioning.
If bilateral repair is performed, document each orbit separately with distinct intraoperative findings for each side.
Medical necessity narrative should address functional deficits — enophthalmos, diplopia, restricted gaze — not cosmetic rationale alone.
If a co-surgeon or surgical team is used (modifier 62), each surgeon must submit a separate operative note documenting their distinct intraoperative role.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 51 Multiple procedures 52 Reduced services 57 Decision for surgery 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 XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 21390 covers open surgical repair of an orbital floor blowout fracture using a periorbital approach, where the surgeon places an alloplastic or other implant to restore orbital floor integrity and volume. The implant — synthetic mesh, porous polyethylene, or similar material — is included in the procedure descriptor, meaning the surgical work of implant placement is bundled into the code. Implant material costs are a separate billing consideration that varies sharply by payer: Medicare assigns a non-covered (N1) status indicator to implant-specific HCPCS codes such as L8610 under the facility payment systems, which frequently means ASCs absorb implant costs outright.

This code carries a 90-day global period. All routine post-op visits, dressing changes, and minor wound care through day 90 are bundled. Any unrelated E/M services in that window require modifier 24; a related staged procedure requires modifier 58, which resets the global clock. The code sits in the fracture and dislocation procedures on the head section and is distinct from 21386 (periorbital approach without implant) and 21395 (periorbital approach with bone graft). Laterality modifiers LT and RT are the standard approach for bilateral presentations, though payer behavior on bilateral orbital floor repairs varies — some carriers require modifier 50 on a single line, others require RT/LT on separate lines.

Otolaryngology is the top billing specialty per CMS utilization data, though plastic surgery and oral and maxillofacial surgery also bill this code. Site-of-service matters: HOPD and ASC payments differ substantially (see the Site of Service comparison on this page). Johns Hopkins Health Plans designated 21390 as outpatient surgery effective October 1, 2025, meaning inpatient billing for this procedure will face site-of-service scrutiny at payers following similar CMS guidance.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (10.95) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (21.21) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	10.95
Practice expense RVU	8.79
Malpractice RVU	1.47
Total RVU	21.21
Medicare national rate	$708.43
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	$708.43
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI G2) Ambulatory surgical center (freestanding)	$3,025.62

Common denial reasons

The recurring reasons claims for CPT 21390 get rejected.

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

Operative note uses generic approach language instead of explicitly documenting the periorbital approach, triggering a downcoding to 21386.
Implant cost billed separately under L8610 denied by Medicare and many Medicaid payers due to non-covered (N1) status indicator — implant bundled into procedure payment.
Bilateral repair billed with incorrect modifier syntax — payer requires RT/LT on separate lines but claim submitted with modifier 50 on a single line, or vice versa.
Post-op E/M visits billed without modifier 24 during the 90-day global period, automatically bundled and denied.
Inpatient site of service billed after payer has adopted CMS outpatient surgery designation for 21390, resulting in site-of-service denial.

Frequently asked questions

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

01What is the difference between CPT 21386 and CPT 21390?

Both use a periorbital approach for open orbital floor blowout fracture repair. 21390 is the correct code when an alloplastic or other implant is placed. 21386 is used when no implant is placed. Using 21386 when an implant is documented is a coding error; the operative note controls which code applies.

02Can I separately bill the implant cost under L8610?

For Medicare and most Medicaid plans, L8610 carries a non-covered (N1) status indicator, meaning the implant payment is considered bundled into the 21390 rate and will not be separately reimbursed. For commercial payers without a carve-out, you can attempt L8610 with a supporting invoice, but expect frequent denials and be prepared to appeal with cost documentation.

03How do I bill bilateral orbital floor repairs with 21390?

Most commercial payers and Medicare want RT on the first line (no modifier reduction) and LT on the second line with modifier 51, or separate lines with RT and LT only. Some payers accept modifier 50 on a single line. Check your MAC and payer-specific guidelines before submitting — billing method mismatches are a common denial trigger for bilateral orbital cases.

04What modifiers apply during the 90-day global period?

Modifier 24 for unrelated E/M visits, modifier 25 for a significant separately identifiable E/M on the day of surgery, modifier 58 for a staged or related planned return procedure (resets the global clock), modifier 78 for an unplanned return to the OR for a related complication, and modifier 79 for an unplanned unrelated procedure during the global period.

05Is 21390 payable in an ASC setting?

Yes. 21390 is covered in ASCs. Johns Hopkins Health Plans and CMS guidance effective October 1, 2025 classify this as outpatient surgery, meaning inpatient billing will draw site-of-service scrutiny. ASC payment is lower than HOPD — see the Site of Service comparison on this page for current figures.

06When should modifier 62 be used with 21390?

Use modifier 62 when two surgeons — for example, a craniofacial surgeon and an ophthalmologist — each perform distinct, documented portions of the orbital repair as co-primary surgeons. Each must submit a separate operative note describing their individual work. Expect each surgeon's claim to be reimbursed at approximately 62.5% of the total allowable.

07Does modifier 22 apply to complex orbital floor repairs?

Modifier 22 is appropriate when the procedure requires substantially more work than typical — for example, severely comminuted fractures, significant scarring from prior trauma, or markedly increased operative time. Document the specific factors in the operative note that increased complexity. Without that documentation, payers will ignore the modifier and pay at the standard rate.

Sources & references

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

Mira Scribe

Mira's AI scribe captures the surgical approach by name (periorbital), implant type and material, fracture laterality, intraoperative findings at the orbital floor, and reduction technique directly from dictation. It flags operative notes that omit approach specificity or implant documentation — the two most common triggers for downcoding to 21386 or implant-cost denials.

See how Mira captures CPT 21390 documentation