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Billing code 21123: Chin augmentationMedicare rate & RVUs

Sliding genioplasty with an interpositional bone graft repositions the chin segment while adding projection or height for selected chin deficiencies.

CMS RVU26DEffective Oct 1, 2026109 payment localities

Medicare pays $777.91 for 21123 nationally in a facility.

Medicare rate · 21123

Chin augmentation

Swap in your local Medicare rate.

Work RVUs
11.06
Total RVUs
23.29
Global days
090

National rate · 2026

$777.91

Facility setting, before claim adjustments.

See every locality for 21123 → · Billed by an NP, PA or therapist? →

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 10 sections
  1. Medicare rate
  2. What 21123 covers
  3. By payment locality
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Similar codes
  8. Related codes
  9. Billing questions
  10. Sources

What 21123 covers

A surgeon cuts and moves the chin portion of the mandible, then places bone between the repositioned segment and the remaining jaw to augment the chin. This approach may be selected when sliding the bone alone would leave a gap or provide insufficient projection or height. Oral and maxillofacial, plastic, or craniofacial surgeons typically perform the operation in a hospital or ambulatory surgical setting.

Report 21123 when the operative record supports both a sliding chin osteotomy and augmentation with an interpositional graft. Document the osteotomy, the segment’s repositioning, and the graft placement; simple augmentation without sliding or a sliding osteotomy without grafting points to a different code. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. When multiple procedures occur in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Assistant-at-surgery payment may be available; co-surgeon payment requires supporting documentation, and team-surgery payment is not permitted.

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 21123 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

21123 office and facility rates by payment locality
Payment localityOfficeFacility
AlabamaUnavailable$710.23
Alaska*Unavailable$961.53
ArizonaUnavailable$759.17
ArkansasUnavailable$701.81
AtlantaUnavailable$795.50
AustinUnavailable$793.09
BakersfieldUnavailable$797.95
Baltimore/Surr. CntysUnavailable$822.46
BeaumontUnavailable$742.16
BrazoriaUnavailable$765.84

21123 rates by state

Office rate range in each state. Select a state to see its payment localities.

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Local rates. Clear comparisons.

Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.

View every state and territory as a table
21123 office rate range by state
State / territoryOffice rate rangeLocalities
AKNo published base rate1
ALNo published base rate1
ARNo published base rate1
AZNo published base rate1
CANo published base rate29
CONo published base rate1
CTNo published base rate1
DCNo published base rate1
DENo published base rate1
FLNo published base rate3
GANo published base rate2
GUNo published base rate1
HINo published base rate1
IANo published base rate1
IDNo published base rate1
ILNo published base rate4
INNo published base rate1
KSNo published base rate1
KYNo published base rate1
LANo published base rate2
MANo published base rate2
MDNo published base rate3
MENo published base rate2
MINo published base rate2
MNNo published base rate1
MONo published base rate3
MSNo published base rate1
MTNo published base rate1
NCNo published base rate1
NDNo published base rate1
NENo published base rate1
NHNo published base rate1
NJNo published base rate2
NMNo published base rate1
NVNo published base rate1
NYNo published base rate5
OHNo published base rate1
OKNo published base rate1
ORNo published base rate2
PANo published base rate2
PRNo published base rate1
RINo published base rate1
SCNo published base rate1
SDNo published base rate1
TNNo published base rate1
TXNo published base rate8
UTNo published base rate1
VANo published base rate2
VINo published base rate1
VTNo published base rate1
WANo published base rate2
WINo published base rate1
WVNo published base rate1
WYNo published base rate1

How the 21123 rate is calculated

Each of 21123’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 · 21123

RVUs × geographic indexes × conversion factor

Swap in your local Medicare rate.

Work 11.06Practice expense 10.62Malpractice 1.61

23.2900 adjusted RVUs×$33.4009 conversion factor=$777.91

All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.

Payment rules and modifiers for 21123

21123 has a 90-day global period: related visits in that window are included in the surgery payment.

CMS payment indicators · 21123

Chin augmentation

RuleCMS valueWhat it means
Global period090Major surgery: the day before, the day of, and 90 days after are included.
Multiple procedures2Standard reduction: highest-valued procedure at 100%, others at 50%.
Bilateral (modifier 50)0The 150% bilateral adjustment doesn’t apply.
Assistant at surgery (80/81/82/AS)2Paid.
Co-surgeons (62)1Permitted with supporting documentation.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.
Split (54/55/56)0.10/0.69/0.21Share of the payment for pre-op, the procedure itself, and post-op care.

Global surgery period · 21123

Chin augmentation

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.

  • 24 Unrelated E/M visit by the same physician
  • 79 Unrelated procedure (starts its own global period)
  • 58 Staged, more extensive, or therapy procedure that was planned
  • 78 Unplanned return to the operating room for a related complication
SurgeryVisit
Sep 23, 2026Jan 10, 2027

Pre-op dayGlobal period

What modifiers do to the payment

Modifier 51 · payment effect

With and without the modifier

21123 without 51 · national facility

$777.91

Chin augmentation

21123-51 · Second procedure: 50%

$388.96

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%).

When to use modifier 51

21123 compared with similar codes

Compare codes

21123 vs 21120 vs 21121 vs 21122 vs 21125: national Medicare rates

Swap in your local Medicare rate.

  • 21123
    Chin augmentation · 11.06 wRVU
    —
  • 21120
    Chin augmentation · 4.97 wRVU
    $715.45
  • 21121
    Sliding genioplasty · 7.61 wRVU
    $649.98
  • 21122
    Sliding genioplasty · 8.49 wRVU
    —
  • 21125
    Mandibular augmentation · 10.53 wRVU
    $2,595.58

How to choose

21120Chin augmentation
Choose 21120 for chin augmentation without a sliding osteotomy. 21123 involves moving the chin segment and augmenting it with an interpositional graft.
21121Sliding genioplasty
21121 is a single-piece sliding genioplasty without the graft augmentation represented by 21123.
21122Sliding genioplasty
21122 describes sliding genioplasty with two or more osteotomies. 21123 is distinguished by interpositional graft augmentation.
21125Mandibular augmentation
21125 addresses augmentation of the mandibular body or angle; 21123 is for sliding repositioning and graft augmentation of the chin.

Codes related to 21123

Related codes aren’t interchangeable: bill the code that matches the service performed.

Codes related to 21123
CodeHow it relatesNational office range
Same family
21120Chin augmentationGenioplasty augmentation without the sliding osteotomy and interpositional graft combination.$627.40–$948.72
21121Sliding genioplastySliding genioplasty using a single-piece osteotomy without graft augmentation.$584.18–$826.56
21122Sliding genioplastySliding genioplasty involving multiple osteotomies rather than this graft-augmentation approach.No office rate
Used instead
21125Mandibular augmentationMandibular body or angle augmentation, rather than a sliding chin-segment procedure.$2,265.30–$3,589.45

21123 billing questions

How is 21123 different from 21121?

21123 describes a sliding chin osteotomy with interpositional graft augmentation. Use 21121 for a single-piece sliding genioplasty without that graft augmentation.

Can 21123 be reported with 21120 for the same chin?

Do not report a second genioplasty code for the same chin work simply to represent the graft. Choose the code that matches the operation performed.

Should modifier 50 be appended for work on both sides?

No. CMS identifies bilateral adjustment as inappropriate for this code; modifier 50 does not describe the midline chin procedure.

What documentation supports reporting 21123?

The operative report should identify the sliding osteotomy, how the chin segment was repositioned, and placement of an interpositional bone graft for augmentation.

How does the 90-day global period affect postoperative visits?

The day-before preoperative visit and 90 days of related postoperative care are included in the global period.

Can an assistant or co-surgeon be reported?

Assistant-at-surgery payment may be available. Co-surgeon payment requires supporting documentation; team-surgery payment is not permitted.

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
RVUs for 21123PPRRVU2026_Oct_nonQPP.csv, line 1,880 (RVU26D)

Open CMS sourceHow we calculate rates

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