Surgical · Other

Segmental mandibular osteotomy with genioglossus muscle advancement — the lower jaw is cut in segments, repositioned, and the tongue-base muscle attachment is advanced forward.

Verified May 8, 2026 · 6 sources ↓

Medicare: $906.17
Total RVUs: 27.13
Global, days: 90
Region: Other

Drawn from CMSAaomsEmednyFindacode

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify that a segmental mandibular osteotomy was performed — not just 'jaw surgery' or 'standard approach'
Explicitly document genioglossus advancement as a performed component, including direction and method of fixation
State the functional indication (e.g., skeletal malocclusion, obstructive sleep apnea with documented AHI, jaw deformity with functional impairment) to support medical necessity
Record intraoperative bone cuts, segment count, and fixation hardware used (plates, screws, wires)
Document the preoperative diagnostic workup, including imaging (cephalometric radiographs, CT) and, for OSA cases, polysomnography results
For OSA-related cases, note failed or contraindicated non-surgical alternatives (e.g., CPAP failure) per payer LCD requirements
If additional procedures were performed at the same session (e.g., 21685, 21196), document each separately with distinct operative descriptions

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 62 Co-surgeons 74 Discontinued post-anesthesia 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 21199 describes a segmental mandibular osteotomy combined with genioglossus advancement. The surgeon incises the mandible in segments, repositions the bone, and advances the genioglossus muscle anteriorly — a technique used to correct jaw deformities and, critically, to pull the tongue base forward to relieve upper airway obstruction in obstructive sleep apnea (OSA) surgical protocols.

This code sits in the mandibular osteotomy family alongside 21198 (segmental osteotomy without genioglossus advancement). The advancement component is what distinguishes 21199 and drives its higher complexity. When performed as part of a multi-level OSA surgical session, 21199 is frequently billed with 21685 (hyoid myotomy and suspension) or with maxillary osteotomy codes — each requiring careful modifier and NCCI edit review before submission.

The 90-day global period covers the surgery date, the day-before visit, and all routine postoperative management through day 90. Any unrelated E/M or procedure in that window requires modifier 24 or 79, respectively. Reconstructive versus cosmetic determination is payer-specific; document medical necessity explicitly — payers routinely post coverage policies distinguishing functional reconstruction from aesthetic correction, and that distinction drives coverage decisions.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	16.31
Practice expense RVU	8.45
Malpractice RVU	2.37
Total RVU	27.13
Medicare national rate	$906.17
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	$906.17
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 21199 get rejected.

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

Cosmetic versus reconstructive determination — payer denies without explicit functional impairment documentation or OSA diagnostic data
Missing genioglossus advancement documentation — operative note describes osteotomy only, not the muscle advancement, making 21199 unsupported over 21198
Global period conflict — a postoperative E/M billed without modifier 24 triggers automatic bundling denial
Medical necessity not established — no preoperative imaging, AHI data, or failed conservative treatment documented in the record
Same-session procedure bundling — co-billed codes (e.g., 21685) denied without proper modifier 59 or XS to establish distinct anatomic or procedural separation per NCCI PTP edits
Prior authorization absent or expired — many commercial payers require pre-auth for mandibular osteotomy procedures, especially OSA-related indications

Frequently asked questions

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

01What distinguishes 21199 from 21198?

21198 is a segmental mandibular osteotomy without genioglossus advancement. 21199 requires that the genioglossus muscle be advanced anteriorly as part of the same operative session. If the advancement is performed but not documented, payers will downcode to 21198.

02Can 21199 and 21685 be billed together for an OSA case?

Yes — hyoid myotomy and suspension (21685) is a distinct anatomic procedure from the mandibular osteotomy and genioglossus advancement in 21199. Bill both with modifier 51 on the lower-value code. Confirm NCCI PTP edit status and apply modifier 59 or XS if an edit exists, provided the procedures are genuinely separate.

03Is 21199 covered for obstructive sleep apnea?

Coverage is payer-dependent. Many commercial payers and some MACs cover it when OSA is documented with polysomnography, CPAP failure or contraindication is established, and the surgeon documents how genioglossus advancement addresses the anatomic obstruction. Review the applicable LCD or commercial policy before submitting — cosmetic exclusions are broadly written and can sweep in functional cases without proper documentation.

04What global period applies and what does it cover?

21199 carries a 90-day global period under CMS Physician Fee Schedule 2026. The global includes the day-before visit, the surgery, and all routine postoperative care through day 90. Unrelated E/M services in the global window need modifier 24. Unrelated procedures need modifier 79. A staged or planned related procedure needs modifier 58.

05When is modifier 22 appropriate for 21199?

Use modifier 22 when the procedure is substantially more complex than typical — for example, revision after prior mandibular surgery, significant scarring, or unusually prolonged operative time. You need documentation in the operative note that explains the increased complexity, and expect a payer request for records. Modifier 22 without supporting documentation is a common audit flag.

06How does site of service affect reimbursement for 21199?

HOPD and ASC payments differ materially — see the Site of Service comparison on this page. The facility rate applies when the surgeon operates in a hospital or ASC; the non-facility rate applies in an office setting, though 21199 is rarely performed outside a facility. Geographic GPCI adjustments also apply to the Medicare Physician Fee Schedule rate.

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 segmental osteotomy technique, number of bone cuts, genioglossus advancement details (including direction and fixation method), functional indication, and hardware placement from dictation. This prevents the most common denial trigger for 21199: an operative note that documents the osteotomy but omits the advancement, leaving the code unsupported over the lower-complexity 21198.

See how Mira captures CPT 21199 documentation