Add-on code for a complete (cylindrical) intercalary allograft — donor bone shaped and fixed to bridge a full circumferential defect in a long bone between two joints.
Verified May 8, 2026 · 5 sources ↓
- Medicare
- $648.65
- Total RVUs
- 19.42
- Global, days
- Region
- Other
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 5 cited references ↓
- Explicitly state that the allograft is intercalary and complete (cylindrical/full-circumferential), not hemicylindrical — the distinction determines 20933 vs. 20934.
- Identify the primary resection procedure by CPT code; 20934 is only valid as an add-on to approved host codes (23210, 23220, 24150, 25170, 27075–27077, 27365, 27645, 27704).
- Document the extent and location of the bone defect — diaphyseal segment between joints — with measurements confirming an intercalary, not articular, position.
- Record templating process, donor tissue source (allograft), shaping steps, placement technique, and method of internal fixation used to secure the graft.
- Confirm tumor pathology or diagnosis driving the resection; oncologic indication is standard context for this code and supports medical necessity.
- Note absence of concurrent free vascularized bone graft or arthroplasty — using those codes with 20934 violates published exclusions.
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 5 cited references ↓
CPT 20934 is an add-on code reporting a complete intercalary allograft: a cylindrical segment of donor bone templated, cut, shaped, and internally fixed to reconstruct a full-thickness gap in the cortex of a long bone situated between joints. 'Intercalary' means the graft spans a mid-diaphyseal defect, not an articular surface. 'Complete' (as opposed to the hemicylindrical +20933) means the allograft encircles the full circumference of the bone. The work of templating, fashioning the donor segment to fit, placing it, and securing it is bundled into this code — do not separately report those steps.
This code is almost exclusively used in oncologic surgery: after tumor resection that leaves a segmental diaphyseal defect in bones such as the femur, humerus, tibia, radius, or fibula. Valid primary procedure hosts include 23210, 23220, 24150, 25170, 27075, 27076, 27077, 27365, 27645, and 27704. A long exclusion list applies — notably, do not report 20934 alongside 20932, 20933, free vascularized fibula codes (20955–20957, 20962), or most arthroplasty codes. The global period is ZZZ, meaning it inherits the global package of the primary procedure it accompanies.
Because the code was introduced in 2019 as part of a three-code allograft family (20932–20934), payers unfamiliar with the distinction between osteoarticular (20932), hemicortical (20933), and complete intercalary (20934) grafts will sometimes deny or downcode. The operative note must make the cylindrical, full-circumferential nature of the reconstruction explicit — the difference between 20933 and 20934 is entirely documentation-driven.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
| Work RVU | 12.68 |
| Practice expense RVU | 4.04 |
| Malpractice RVU | 2.7 |
| Total RVU | 19.42 |
| Medicare national rate | $648.65 |
| Global period | 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 | $648.65 |
Common denial reasons
The recurring reasons claims for CPT 20934 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Billed with an ineligible primary procedure — payers reject 20934 when the host code is not on the approved list (e.g., arthroplasty codes such as 27130 or 27448).
- Operative note describes a hemicylindrical (partial cortex) reconstruction, triggering downcoding to 20933 or outright denial of 20934.
- Reported alongside excluded codes (20932, 20933, 20955–20957, 20962, or arthroplasty codes), triggering NCCI bundling edits.
- Missing or vague documentation of the full-circumferential nature of the graft — auditors cannot verify 'complete' vs. 'partial' without explicit dictation.
- Payer applies a non-covered service policy for allograft procedures or requires prior authorization that was not obtained before surgery.
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01Can I report 20934 as a standalone code?
02What is the difference between 20933 and 20934?
03Can 20934 be billed with arthroplasty codes like 27130?
04Is the templating and shaping of the donor bone separately billable?
05Can 20934 be reported with free vascularized bone graft codes?
06Does modifier 62 (two surgeons) apply to 20934?
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 surgeon's dictation of graft geometry (full circumferential vs. partial), diaphyseal defect dimensions, templating steps, donor tissue source, and fixation method — then flags the note if 'complete' cylindrical language is absent. That single flag prevents the most common 20934 denial: an operative note that doesn't distinguish the reconstruction from a hemicortical 20933.
See how Mira captures CPT 20934 documentation