Billing code 21121: Sliding genioplastyMedicare rate & RVUs in Illinois
Reports a single-piece chin osteotomy repositioned to correct chin projection, asymmetry, or contour by moving the bone segment.
Medicare pays $634.44–$691.23 for 21121 in the office in Illinois, from Rest Of Illinois to Chicago. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
On this page 9 sections
What 21121 covers
This operation reshapes the chin by cutting the mandibular symphysis as one segment, moving that segment to a planned position, and securing it. Oral and maxillofacial surgeons and plastic surgeons perform it in an operating room for concerns such as chin retrusion, excess projection, asymmetry, or vertical contour. It may be performed alone or as part of orthognathic reconstruction.
Choose 21121 when the operative report documents one sliding bone segment; a multisegment osteotomy or added augmentation changes the code selection. Document the osteotomy configuration, direction of movement, fixation, and any graft or implant work. CMS assigns a 90-day major-surgery global: the day-before preoperative visit and related postoperative care through day 90 are included. For multiple procedures in one session, the highest-valued procedure is paid in full and others are subject to the standard 50% reduction. CMS permits assistant-at-surgery payment, but not co-surgeon or team-surgery payment. The midline chin procedure is reported without modifier 50; bilateral adjustment is inappropriate.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Where 21121 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
4 payment localities
$634.44 to $691.23
| Payment locality | Office | Facility |
|---|---|---|
| Chicago | $691.23 | $527.41 |
| East St. Louis | $650.11 | $500.15 |
| Rest Of Illinois | $634.44 | $485.62 |
| Suburban Chicago | $684.10 | $516.70 |
How the 21121 rate is calculated
Each of 21121’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · 21121
RVUs × geographic indexes × conversion factor
Swap in your local Medicare rate.
Work 7.61Practice expense 10.98Malpractice 0.87
All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.
Payment rules and modifiers for 21121
21121 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 21121
Sliding genioplasty
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 090 | Major surgery: the day before, the day of, and 90 days after are included. |
| Multiple procedures | 2 | Standard reduction: highest-valued procedure at 100%, others at 50%. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 2 | Paid. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
| Split (54/55/56) | 0.10/0.69/0.21 | Share of the payment for pre-op, the procedure itself, and post-op care. |
Global surgery period · 21121
Sliding genioplasty
90-day global period ends
Dec 30, 2026
Covers Sep 30, 2026 through Dec 30, 2026 (92 days, including the day before surgery).
Visit on Oct 31, 2026
Day 30 of the 90-day post-op period: related follow-up care is included in the surgical payment.
Pre-op dayGlobal period
What modifiers do to the payment
Modifier 51 · payment effect
With and without the modifier
21121 without 51 · national office
$649.98
Sliding genioplasty
21121-51 · Second procedure: 50%
$324.99
When this isn’t the highest-valued procedure in the session, Medicare pays 50% of its fee schedule amount (the highest is paid at 100%).
21121 compared with similar codes
Compare codes
21121 vs 21120 vs 21122 vs 21123: national Medicare rates
Swap in your local Medicare rate.
How to choose
- 21120Chin augmentation
- 21120 describes augmentation of the chin. Choose 21121 when the surgeon repositions a single osteotomized bone segment instead.
- 21122Sliding genioplasty
- 21122 is for a sliding osteotomy divided into two or more segments; 21121 is the single-segment procedure.
- 21123Chin augmentation
- 21123 includes augmentation with the sliding osteotomy. Use 21121 when the documented procedure is a single-piece sliding osteotomy without that augmentation.
21121 billing questions
How does 21121 differ from 21122?
21121 describes a sliding genioplasty using one bone segment. Use 21122 when the osteotomy divides the chin into two or more segments.
When is 21123 used instead?
Use 21123 when augmentation is performed with the sliding osteotomy. The operative report should identify the augmentation material or graft work.
Can modifier 50 be reported?
No. The chin is a midline site for this procedure, and CMS identifies modifier 50 as inappropriate.
Can an assistant surgeon be paid?
CMS permits assistant-at-surgery payment for 21121. Co-surgeon and team-surgery payment are not permitted for this code.
What postoperative care is included?
The 90-day global includes the day-before preoperative visit and related postoperative care through day 90.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file lines behind this rate
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