Impression and custom preparation of an interim obturator prosthesis — a temporary device fabricated to close the maxillary defect created after partial or total maxillectomy.
Verified May 8, 2026 · 4 sources ↓
- Medicare
- $1,521.75
- Total RVUs
- 45.56
- Global, days
- 90
- Region
- Other
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 4 cited references ↓
- Document the maxillary defect explicitly — extent of resection, defect classification (e.g., Aramany class), and date of prior resection surgery.
- Specify that the prosthesis is interim/temporary, not surgical or definitive, to distinguish from 21076 and 21080.
- Record the impression technique, materials used, and that a custom device was fabricated — not an off-the-shelf appliance.
- Include the treating diagnosis (ICD-10) linking the obturator need to the underlying pathology, typically a malignant or benign maxillary neoplasm.
- Note the provider performing the service and their role — maxillofacial prosthodontist, oral surgeon, or qualified designee.
- Document patient's functional status indicators (speech, swallowing, oral competence) that justify the interim prosthesis at this stage rather than proceeding directly to a definitive device.
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 4 cited references ↓
CPT 21079 covers taking an intraoral impression of the surgical defect site and fabricating an interim obturator prosthesis following maxillary resection. The interim obturator is a temporary appliance — distinct from the surgical obturator placed at the time of resection (21076) and the definitive obturator fitted once the surgical site has stabilized (21080). It bridges the rehabilitation gap while post-surgical edema resolves and tissue remodeling occurs, typically weeks to a few months after resection.
This code is billed by the maxillofacial prosthodontist or oral/maxillofacial surgeon performing the impression and prosthesis preparation, not by the resecting surgeon unless that surgeon also fabricates the device. The 90-day global period means routine follow-up adjustments and check appointments related to the interim obturator are bundled through day 90. Separate services unrelated to the prosthesis require modifier 24.
Site-of-service payment is dramatically different for this code: the HOPD rate far exceeds the ASC rate (see the Site of Service comparison table). Most fabrication work occurs in a clinic or prosthetics lab setting, so confirm the place-of-service code matches where the impression and preparation actually took place. Payers vary on whether a separate lab fee is separately billable or bundled into 21079.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
| Work RVU | 21.75 |
| Practice expense RVU | 21.26 |
| Malpractice RVU | 2.55 |
| Total RVU | 45.56 |
| Medicare national rate | $1,521.75 |
| 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 | $1,521.75 |
HOPD (APC 5164) Hospital outpatient department | $3,387.27 |
ASC (PI P3) Ambulatory surgical center (freestanding) | $713.65 |
Common denial reasons
The recurring reasons claims for CPT 21079 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Wrong prosthesis type billed — payer downcodes to 21076 (surgical obturator) or 21080 (definitive obturator) if documentation doesn't clearly establish the interim phase.
- Missing or vague resection history — claim denied when operative report from the prior maxillectomy is not on file or not referenced in the note.
- Place-of-service mismatch — impressions taken in clinic billed with a facility POS tied to HOPD rates without corresponding facility claim.
- Lack of medical necessity documentation — payers require diagnosis linkage showing active maxillary defect; claims without supporting ICD-10 are rejected.
- Global period conflict — adjustments or follow-up visits billed separately within the 90-day global without modifier 24 appended.
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 4 cited references ↓
01What distinguishes 21079 from 21076 and 21080?
02Who should bill 21079 — the resecting surgeon or the prosthodontist?
03Does the 90-day global period bundle all follow-up adjustments?
04Is prior authorization typically required for 21079?
05Can 21079 and 21080 be billed for the same patient during the same treatment course?
06Why is the ASC payment for 21079 so much lower than the HOPD 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 defect classification, resection history, impression technique and materials, and the explicit designation of the prosthesis as interim rather than surgical or definitive. That specificity prevents downcoding to 21076 or 21080 — the two most common recode errors on obturator claims — and satisfies payer medical necessity requirements that link the device to a documented maxillary defect.
See how Mira captures CPT 21079 documentation