CPT code 21122: Genioplasty sliding osteotomy billing guide

Key takeaways

CPT code 21122 covers a genioplasty performed with two or more sliding osteotomies of the chin.

The osteotomy count is what separates 21122 from 21121, so the operative note must describe every cut.

Medicare rates reset each January, so check the current facility and non-facility figures before you bill.

US claims pair the code with an M26 diagnosis, because ICD-10-CM has no K07 category at all.

Practice management software like Pabau links modifiers, diagnoses, and authorization status to the patient record.

CPT code 21122 is the billable code for a genioplasty performed with two or more sliding osteotomies of the chin. Payers read the osteotomy count in the operative note to decide whether a claim belongs here or under 21121.

This guide covers the descriptor, modifier rules, 2026 fee schedule mechanics, the ICD-10-CM crosswalk, and the documentation that supports a clean claim.

Billing teams at oral and maxillofacial surgery practices and cosmetic surgery practices meet this code when chin repositioning needs correction in more than one plane. Knowing where 21122 starts and 21121 ends prevents undercoding and overcoding alike.

CPT code 21122: Definition and clinical description

The official AMA CPT descriptor reads: Genioplasty; sliding osteotomies, 2 or more osteotomies (eg, wedge excision or bone wedge reversal for asymmetrical chin). The code sits in the Repair, Revision, and/or Reconstruction Procedures on the Head section of the CPT manual. Its genioplasty range runs from 21120 to 21123.

Surgeons use it when the chin is repositioned through two or more separate cuts in the mandibular symphysis. The freed segment is then advanced, retracted, or rotated. Multiple cuts allow three-dimensional movement that a single straight osteotomy cannot achieve, such as vertical shortening combined with horizontal advancement.

What the sliding osteotomy procedure involves

A sliding genioplasty separates a segment of the chin bone and moves it to a new position before plating it in place. The code applies when the surgeon makes two or more separate cuts to achieve that movement.

A single horizontal cut is coded 21121, because one cut only translates the segment in one plane. Two or more cuts let the surgeon reshape the segment itself.

Three scenarios usually call for more than one cut:

• Asymmetry correction that needs a wedge removed
• Vertical height reduction combined with horizontal advancement
• Rotation of the chin segment to correct a midline deviation

• Step 1: Incision. A mucosal incision is made intraorally at the vestibule, below the lower lip, exposing the anterior mandible.
• Step 2: Periosteal elevation. The soft tissue is elevated from the bone to visualize the inferior border and mental nerve foramina bilaterally.
• Step 3: First osteotomy. A horizontal cut is made below the mental foramina with a reciprocating or oscillating saw.
• Step 4: Additional osteotomy or osteotomies. One or more further cuts allow wedge removal, vertical shortening, or segmental reshaping. This is the clinical distinction that justifies 21122 over 21121.
• Step 5: Repositioning and fixation. The freed segment is moved to the planned position and secured with titanium plates and screws.
• Step 6: Wound closure. The periosteum and mucosa are closed in layers.

The operative report has to identify each osteotomy and its purpose. Without that detail, payers downcode to 21121 or deny the claim outright.

How 21122 compares with 21120, 21121, and 21123

Four codes cover genioplasty in the CPT manual. Picking the wrong one is the most common error on these claims, and 21121 and 21122 are the pair coders confuse most. The same descriptor-first logic applies across other specialty families, including the IVF CPT codes. The table below sets all four genioplasty codes side by side.

CPT 21120 involves no osteotomy at all, so augmentation versus sliding is the first decision point. Between 21121 and 21122, the osteotomy count in the operative note settles it.

CPT 21123 adds interpositional bone grafts to a sliding genioplasty, and the descriptor already includes obtaining the autograft. That means the harvest is bundled into 21123 rather than billed as a separate service.

Applicable modifiers for CPT code 21122

Modifier selection follows standard NCCI bundling rules, which CMS updates quarterly. Check modifier applicability against the current CMS Physician Fee Schedule edits before you bill. The table below covers the modifiers that come up most often on genioplasty claims.

Modifier -51 is not universal. Medicare and many commercial payers recognize it, while others want -59 or the X modifier subset instead. Confirm each payer’s rule before submission.

Fee schedule and reimbursement in 2026

Genioplasty reimbursement under Medicare is a surgical global package. It covers the preoperative visits, the procedure itself, and standard postoperative care.

Payment depends on geographic adjustment, place of service, and the annual conversion factor. Verify the current figures in the CMS MPFS look-up tool for the applicable payment year.

Three RVU components drive the payment: physician work, practice expense, and malpractice. Each one is adjusted by your locality’s GPCI values, then multiplied by the year’s conversion factor. Run the numbers for your own contractor region rather than working from a national average.

ICD-10-CM codes used with CPT 21122

Payers want a linked ICD-10-CM diagnosis that establishes medical necessity. The diagnosis has to reflect what the record documents. Never pick a code just to satisfy coverage criteria when it does not match the patient’s condition. The table below lists the codes that fit genioplasty indications, grouped by clinical picture.

One trap catches US coders repeatedly. Plenty of genioplasty crosswalks list K07.0, K07.1, and K07.29 for jaw anomalies, and those are WHO ICD-10 codes rather than ICD-10-CM ones.

The US clinical modification has no K07 category at all, because K06 is followed by K08. A K07 code on a US claim rejects before a payer ever reviews it, so jaw anomalies belong in the M26 category.

You can check the crosswalk against the AAPC code lookup, which lists associated diagnoses and coverage policies. Confirm that the diagnosis code is valid for the date of service. ICD-10-CM updates take effect every October 1.

Documentation requirements for CPT code 21122

The operative report is the first document a payer examines on audit. Since the code turns on the number of osteotomies, the report has to make each cut unambiguous. Practices working from structured clinical documentation spend less time chasing surgeons for missing operative detail.

• Osteotomy count documented explicitly. The note names each osteotomy and describes its location, direction, and purpose. “Multiple cuts were made” is not enough. Each cut needs its own description. Name the horizontal osteotomy below the mental foramina, then the second oblique cut that removes a 4mm wedge.
• Medical necessity narrative. The preoperative record explains why one cut could not achieve the planned correction. That narrative links the diagnosis to the surgical approach.
• Imaging on file. Preoperative cephalometric radiographs and planning records support necessity for complex skeletal corrections. Payers often ask for them on appeal.
• Anesthesia type and duration. Genioplasty is performed under general anesthesia. Document the start and stop times, and leave the anesthesia codes to the anesthesiologist.
• Postoperative diagnosis consistent with the findings. The diagnosis on the claim should match the operative note. Discrepancies between the two are a common audit trigger.

Prior authorization and insurance coverage

Coverage varies by payer and by clinical indication. Cosmetic genioplasty is almost universally excluded. Functional indications such as skeletal malocclusion, sleep apnea surgery, and post-traumatic deformity may qualify, and each payer applies its own criteria.

The same cosmetic-versus-functional test governs other facial procedures, including CPT 15822.

• Submit the request before scheduling. Most commercial payers and Medicare Advantage plans require prior authorization for facial bone reconstruction. Submitting without it leads to a non-covered denial that cannot be appealed on medical necessity grounds.
• Include the supporting clinical record. Attach the cephalometric analysis, sleep study results, orthodontic records, and the surgeon’s letter of medical necessity. A reusable prior authorization form keeps every submission consistent.
• Document the functional impairment. Payers approve correction when the deformity causes a measurable deficit. A cephalometric measurement alone persuades less than a documented problem, such as an occlusion that orthodontics could not settle.
• Anticipate the common denials. Thin evidence of functional impairment and a diagnosis that reads as cosmetic are the usual two. A procedure outside the coverage policy and an unauthorized out-of-network surgeon follow close behind.

Co-reporting 21122 in orthognathic and sleep apnea cases

Genioplasty is rarely performed on its own at major orthognathic centers. Surgeons correcting skeletal malocclusion with a LeFort I osteotomy or a bilateral sagittal split work in the same field.

They often add a genioplasty in the session to settle chin position. CPT 21122 can be co-reported with those codes, subject to NCCI multiple-procedure rules and each payer’s bundling policy.

Other mandibular work follows the same documentation logic on a combined claim. Interdental fixation under CPT 21110 and open fracture treatment under CPT 21470 both need their own operative detail. Trauma cases can also pair the genioplasty with alveolar ridge repair.

Genioplasty codes also appear in sleep apnea surgical planning, where chin advancement improves tongue base position and airway patency.

When G47.33 is the primary diagnosis, the authorization packet should carry the polysomnography results, evidence of CPAP failure, and an airway assessment. Consistent templates keep that packet the same for every case.

How practice management software supports CPT 21122 billing

Specialty surgical codes create three recurring billing problems: modifier errors, mismatched diagnosis links, and authorizations that nobody tracked. Each one delays payment, and together they hold a meaningful share of accounts receivable in oral and maxillofacial surgery practices.

Practice management software like Pabau handles these at the workflow level instead of during claims correction. For plastic surgery practices and dermatology practices alike, billing stays connected to the clinical record from the point of scheduling. Nothing has to be reassembled from separate systems after the case is done.

• Modifier prompting. When a coder enters 21122, the system flags the applicable modifiers and asks for confirmation before submission. That catches the multi-procedure claim that would otherwise go out bare. Pabau’s claims management software supports modifier-level review at that point.
• Diagnosis linkage. Linking the M26 or G47.33 diagnosis at the encounter, rather than at submission, keeps the claim consistent with the note. Digital patient records carry the diagnosis through to the claim, so nobody re-keys it.
• Authorization tracking. Authorization status, reference numbers, and approval dates sit in the patient record, so no claim goes out ahead of its approval. Automated billing workflows flag the cases that need authorization before they reach the scheduler.
• Operative note templates. Digital clinical forms built for oral surgery capture osteotomy count, location, and purpose in a structured field set. A good template also gets the surgeon out of charting faster.

Practices weighing up systems can compare the options in this guide to plastic surgery software. A closer look at a purpose-built plastic surgery EMR covers what it adds to surgical documentation and billing.

Manage complex surgical billing with fewer errors

Pabau links modifiers, diagnoses, and authorization status to the patient record. Your team can check a CPT 21122 claim before it ever leaves the practice.

Book a demo

Conclusion

Genioplasty claims turn on a few lines of the operative note. Name each cut and its purpose, and 21122 holds up under audit. Say only that multiple cuts were made, and the payer reads the case as 21121 and pays accordingly.

Put the check in the workflow instead of the appeal. Confirm the osteotomy count, the M26 diagnosis, and the authorization number before the claim leaves the practice. That is the difference between payment in three weeks and an argument that runs for three months.

Pabau keeps that check in one place, so modifier selection, diagnosis linkage, and authorization tracking happen before submission rather than after a denial. To see how it works for oral and maxillofacial or plastic surgery billing, book a demo.

Continue your research

Coding another maxillofacial fracture repair? CPT code 21407 walks through open treatment of an orbital fracture with an implant, including the documentation payers ask for.

Billing an excision on the maxilla? CPT code 21049 covers benign tumor and cyst excision, with the modifier rules that apply on combined oral surgery claims.

Need the facial plastic side of the same code family? CPT code 15828 explains rhytidectomy of the cheek, chin, and neck, and where coverage usually lands.

Unsure which NPI belongs on the claim? Type 1 vs Type 2 NPI sets out which identifier a surgeon and a group practice each need, and when.

Want the diagnosis captured cleanly at the visit? Medical diagnosis form gives you a field-by-field structure that keeps the coded diagnosis matched to the note.

Frequently asked questions