Surgical · Other

Surgical bone grafting to the nasal, maxillary (upper jaw), or malar (cheek) areas, including harvest of the graft when autogenous bone is used.

Verified May 8, 2026 · 6 sources ↓

Medicare: $1,793.63
Total RVUs: 53.7
Global, days: 90
Region: Other

Drawn from AaomsAAPCNiermanpmFindacodeCMS

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify the recipient site(s) explicitly: nasal, maxillary, and/or malar — vague 'facial bone graft' language is an audit flag
Document whether bone was harvested from the patient (autograft) or whether allograft/synthetic material was used — this determines modifier 52 applicability
Identify the donor site and harvest technique if autogenous bone was obtained (e.g., anterior iliac crest, posterior iliac crest, local harvest)
State the underlying indication: traumatic defect, congenital deformity, pathologic bone loss, orthognathic reconstruction, or atrophic alveolar bone
Record fixation hardware used if applicable (screws, plates, or wires) as part of the reconstruction narrative
Pre-op imaging (CT or radiographs) confirming osseous defect and post-op documentation of graft placement and fixation

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 25 Significant separate E/M 51 Multiple procedures 52 Reduced services 59 Distinct service 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 6 cited references ↓

CPT 21210 covers complex reconstructive bone grafting to the nasal, maxillary, or malar skeleton. The code inherently includes surgical harvest of the autograft — typically from the anterior or posterior iliac crest or a local donor site. When the surgeon uses freeze-dried, allograft, or synthetic bone material and does not harvest autogenous bone, modifier 52 is required to reflect the reduced scope of work. Billing 21210 without modifier 52 for a non-harvest case is a common audit trigger.

The 90-day global period means all routine post-op care through day 90 is bundled. Sinus lift procedures to the maxilla are reportable under 21210 to medical payers when the clinical scenario meets the complexity threshold — minor socket preservation or simple dental bone grafts do not qualify and should be reported with CDT codes to dental carriers instead. AAOMS explicitly warns against crosswalking CDT D7950/D7953 directly to 21210 without confirming the procedure's intensity justifies it, as inappropriate crosswalking is an upcoding exposure.

This code is not appropriate for straightforward socket preservation or implant site development. It reflects a major reconstructive procedure. When 21210 and 21215 are performed on the same date, apply modifier 51 to the lower-valued procedure. If an E/M is billed the same day, modifier 25 belongs on the E/M — not on the surgical code.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	11.4
Practice expense RVU	40.96
Malpractice RVU	1.34
Total RVU	53.7
Medicare national rate	$1,793.63
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	$1,793.63
HOPD (APC 5165) Hospital outpatient department	$6,048.05
ASC (PI A2) Ambulatory surgical center (freestanding)	$3,025.62

Common denial reasons

The recurring reasons claims for CPT 21210 get rejected.

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

Modifier 52 omitted when no autogenous bone harvest was performed — payer downcodes or denies the full-value claim
Procedure coded as 21210 for simple socket preservation or minor dental bone grafts that don't meet the complexity threshold, flagged as upcoding
Inappropriate CDT-to-CPT crosswalk (D7950 or D7953 mapped directly to 21210) without clinical justification for the higher-intensity code
Missing or insufficient operative note detail — notes that list only 'bone graft to maxilla' without harvest documentation, fixation, or defect description fail audit review
E/M billed same-day without modifier 25, causing the evaluation to be bundled into the surgical global and denied

Frequently asked questions

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

01Is modifier 52 required when using allograft or synthetic bone instead of harvesting from the patient?

Yes. CPT 21210 includes obtaining the graft as part of its base work. When you skip the harvest — using allograft, freeze-dried bone, or synthetic material — the procedure is reduced in scope and modifier 52 must be appended. Bill a correspondingly reduced fee and include an invoice for the graft material cost under CPT 99070 if the surgeon supplied it.

02Can CPT 21210 be billed for a sinus lift?

A sinus lift to the maxilla can be reported as 21210 to a medical payer when the clinical scenario reflects a complex reconstruction. It is not appropriate for straightforward sinus augmentation preceding a simple implant placement. AAOMS guidance requires that the procedure's intensity and degree of reconstruction justify the code's high RVU before crosswalking.

03If 21210 and 21215 are performed the same day, how do you bill them?

Bill both codes. Apply modifier 51 to the lower-valued procedure to flag multiple procedures in the same surgical session. Do not use modifier 50 — these codes designate anatomically distinct sites (maxillary vs. mandibular), not bilateral paired structures, so 50 is not applicable.

04What is the global period for CPT 21210, and what does it cover?

CPT 21210 carries a 90-day global period. All routine post-operative visits, wound checks, and suture/staple removal through day 90 are bundled. Unrelated procedures in that window need modifier 79; a related return to the OR needs modifier 78.

05Can simple socket preservation after tooth extraction be billed as 21210?

No. CPT 21210 is reserved for major osseous reconstruction of the nasal, maxillary, or malar skeleton. Socket preservation and minor alveolar bone grafts associated with routine extractions or straightforward implant site preparation should be reported with the appropriate CDT code to the dental carrier — not crosswalked to 21210 for a medical claim.

06Does modifier 25 belong on the E/M or on 21210 when both are billed the same day?

Modifier 25 goes on the E/M code, not on the surgical code. It signals to the payer that the evaluation was a separately identifiable service distinct from the pre-procedure assessment. Placing it on the surgical code accomplishes nothing and may cause the claim to edit incorrectly.

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 graft recipient site (nasal, maxillary, or malar), whether autogenous bone was harvested and from which donor site, the type of graft material used, fixation method, and the clinical indication driving reconstruction. That specificity prevents the two most common denials on this code: missing harvest documentation that triggers a modifier 52 dispute, and operative notes too vague to survive a complexity audit.

See how Mira captures CPT 21210 documentation