Surgical · Other

Bifrontal reconstruction of the superior-lateral orbital rims and lower forehead, with or without bone grafts including autograft harvest, for conditions such as plagiocephaly, trigonocephaly, or brachycephaly.

Verified May 8, 2026 · 4 sources ↓

Medicare: $1,931.91
Total RVUs: 57.84
Global, days: 90
Region: Other

Drawn from CMSEmedny

Documentation requirements

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

Source · Editorial brief grounded in 4 cited references ↓

Diagnosis name and cranial deformity type (e.g., plagiocephaly, trigonocephaly, brachycephaly) stated explicitly in the operative note
Quantified severity — craniometric measurements or cephalic index supporting medical necessity, not cosmetic intent
Description of functional impairment (e.g., intracranial hypertension, orbital dystopia, airway or visual compromise) when present
Operative note specifying bifrontal approach and whether graft was used; if autograft harvested, document the donor site and technique
Pre-authorization documentation for commercial payers, including imaging studies (CT with 3D reconstruction) supporting the planned reconstruction
Neurosurgical or multidisciplinary team involvement noted when applicable, as many payers require co-management documentation

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 62 Co-surgeons 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 4 cited references ↓

CPT 21175 describes a bifrontal craniofacial reconstruction targeting the superior-lateral orbital rims and lower forehead. The procedure addresses abnormal skull morphology — plagiocephaly, trigonocephaly, and brachycephaly are the canonical examples — through advancement or alteration of the bifrontal segment. Bone grafting, including autograft harvest, is included in the code when performed; don't unbundle a separate graft-harvest code.

This is a 090-day global procedure. All routine post-op care, wound checks, and stitch removals through day 90 are bundled. Bill unrelated E/M services in the global window with modifier 24; use modifier 25 for a significant, separately identifiable E/M on the day of surgery.

Coverage hinges on medical necessity documentation distinguishing reconstructive intent from cosmetic intent. CMS Local Coverage Article A56658 governs this distinction for Medicare. Operative reports that don't clearly name the deformity, quantify severity, or describe functional impairment are the fastest path to a cosmetic-exclusion denial. Payer prior-authorization requirements vary widely — commercial carriers frequently require craniometric measurements and neurosurgical or neurodevelopmental consultation notes before authorizing.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	32.72
Practice expense RVU	19.04
Malpractice RVU	6.08
Total RVU	57.84
Medicare national rate	$1,931.91
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	$1,931.91
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 21175 get rejected.

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

Cosmetic exclusion: payer determines deformity is aesthetic rather than functional — prevented by explicit functional-impairment language in the record
Lack of prior authorization: high-dollar craniofacial procedures almost universally require pre-auth from commercial payers
Unbundled bone graft harvest billed separately — autograft harvest is already included in 21175 and will trigger an NCCI edit
Insufficient medical necessity documentation: operative note lacks craniometric data or diagnosis specificity required by LCD/LCA A56658
Wrong global-period billing: routine post-op visits billed without modifier 24 during the 90-day global window

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 4 cited references ↓

01Is autograft harvest billed separately with CPT 21175?

No. Autograft harvest is bundled into 21175. Billing a separate graft-harvest code will generate an NCCI edit and deny the additional line.

02How do you distinguish 21175 from 21172?

21172 covers reconstruction of the superior-lateral orbital rim and lower forehead unilaterally or in a more limited extent. 21175 is specifically bifrontal — both sides — and is the appropriate code when the reconstruction spans across the full frontal region including both orbital rims.

03What modifier applies if the surgeon bills an E/M visit on the same day as 21175?

Use modifier 57 if the E/M represents the decision for surgery on the day before or day of a major procedure. Use modifier 25 if it is a significant, separately identifiable E/M unrelated to the surgical decision on the same date.

04Does Medicare cover CPT 21175?

Coverage requires the procedure to meet reconstructive — not cosmetic — criteria under CMS Local Coverage Article A56658. Documentation must demonstrate functional impairment or a condition resulting from disease, trauma, or congenital defect. A purely aesthetic correction will be excluded.

05What is the global period for 21175 and what does it include?

21175 carries a 90-day global period. That covers the operative day, the day-before preoperative visit if applicable, and all routine post-op care through day 90. Bill unrelated services during that window with modifier 24.

06Can a co-surgeon bill with 21175?

Yes, when medical necessity for two surgeons is documented and the payer allows it. Each surgeon appends modifier 62. Operative notes must reflect each surgeon's distinct role and the complexity requiring co-surgery.

07Is prior authorization typically required for CPT 21175?

Yes, for nearly all commercial payers and many Medicaid plans. Given the HOPD and ASC payment levels for this code, expect mandatory pre-auth with submission of CT imaging, craniometric data, and clinical notes documenting medical necessity.

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 cranial deformity diagnosis (plagiocephaly, trigonocephaly, brachycephaly), the bifrontal approach, graft use and donor site, and any documented functional impairment from dictation. This prevents the most common denial on 21175 — the cosmetic-exclusion — by ensuring the operative note contains the medical-necessity language payers and auditors require before they'll process a claim at this RVU level.

See how Mira captures CPT 21175 documentation