Arthroscopically aided repair of a unicondylar tibial plateau fracture, with internal fixation when performed; arthroscopy included in the procedure.
Verified May 8, 2026 · 6 sources ↓
- Medicare
- $729.81
- Total RVUs
- 21.85
- Global, days
- 90
- Region
- Knee
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 6 cited references ↓
- Specify which condyle is fractured (medial or lateral) — unicondylar vs. bicondylar determines 29855 vs. 29856
- Describe fracture visualization under arthroscopy, including articular surface assessment and any associated intra-articular pathology
- Document reduction technique and confirm anatomic or near-anatomic alignment achieved arthroscopically
- Record fixation construct used (screw count, plate type, size) if internal fixation was performed
- Note pre-op imaging (X-ray, CT) confirming unicondylar involvement to support code selection on audit
- Dictate the arthroscopic findings explicitly — do not state 'standard approach'; name portals used and compartments inspected
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 6 cited references ↓
CPT 29855 covers arthroscopic-assisted treatment of a proximal tibial (plateau) fracture limited to one condyle — medial or lateral. Internal fixation (screws, plates) is included in the code when performed; you do not report it separately. The arthroscopy itself is also bundled — do not stack a separate knee arthroscopy code.
The unicondylar designation is the critical selection point. If both condyles are involved, step up to 29856. If the fracture involves the intercondylar spine or tibial tuberosity rather than the plateau surface, use 29851. Calcium phosphate subchondral injection without a true plateau fracture reduction is not 29855 — that work maps to Category III code 0707T per AMA CPT Assistant guidance.
29855 carries a 90-day global period. All routine post-op visits, wound checks, and stitch removals through day 90 are bundled. Bill an E/M in that window only for a new or unrelated problem (modifier 24) or a separately identifiable service on the day of surgery (modifier 25 on the E/M). Use modifier 57 on a same-day or day-before E/M if that visit was the decision-for-surgery encounter.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
| Work RVU | 10.49 |
| Practice expense RVU | 9.2 |
| Malpractice RVU | 2.16 |
| Total RVU | 21.85 |
| Medicare national rate | $729.81 |
| 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 | $729.81 |
HOPD (APC 5114) Hospital outpatient department | $7,413.38 |
ASC (PI J8) Ambulatory surgical center (freestanding) | $5,132.37 |
Common denial reasons
The recurring reasons claims for CPT 29855 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Code billed as 29855 when operative note describes bicondylar involvement — should be 29856
- Separate arthroscopy code (e.g., 29870–29999) billed in addition to 29855 — arthroscopy is bundled and will be denied as duplicate
- Calcium phosphate subchondral injection reported as 29855 without documented true plateau fracture reduction — maps to 0707T per AMA guidance
- Routine post-op E/M visits billed without modifier 24 during the 90-day global period
- Missing pre-operative imaging documentation supporting unicondylar fracture diagnosis, triggering medical necessity denial
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 6 cited references ↓
01What is the difference between 29855 and 29856?
02Is the arthroscopy separately billable when reporting 29855?
03Can I bill 29855 when the surgeon injects calcium phosphate into a subchondral defect?
04What global period applies, and what does it cover?
05When is modifier 22 appropriate for 29855?
06How does 29855 differ from 29851?
07Can 29855 be billed bilaterally?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CMS Physician Fee Schedule 2026
- 02aapc.comhttps://www.aapc.com/codes/cpt-codes/29855
- 03kzanow.comhttps://www.kzanow.com/coding-coaches/29855-or-0707t
- 04abos.orghttps://www.abos.org/wp-content/uploads/2019/12/sports-cpt-updated.pdf
- 05aaos.orghttps://www.aaos.org/globalassets/quality-and-practice-resources/coding-and-reimbursement/resident-guide/resident-guide_modifiers.pdf
- 06pmc.ncbi.nlm.nih.govhttps://pmc.ncbi.nlm.nih.gov/articles/PMC7588641/
Mira AI Scribe
Mira's AI scribe captures the condyle involved (medial vs. lateral), arthroscopic portal placement, fracture visualization and reduction technique, and fixation construct details directly from surgeon dictation. This prevents the most common 29855 audit flag: an operative note that fails to confirm unicondylar involvement, which auditors use to downcode or deny the claim outright.
See how Mira captures CPT 29855 documentation