Billing code 29879: Arthroscopic cartilage procedureMedicare rate & RVUs in Guam
Report 29879 for knee arthroscopy that treats a focal articular cartilage defect by abrading or perforating underlying bone to stimulate repair.
CMS doesn’t publish an office rate for 29879 in Guam.
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 9 sections
What 29879 covers
During knee arthroscopy, the surgeon treats a focal articular cartilage defect by removing unstable cartilage and preparing the underlying subchondral bone with abrasion, drilling, or microfracture to encourage marrow-based repair. Orthopedic surgeons commonly perform this in an operating room or ambulatory surgery center for symptomatic cartilage damage. The operative note should identify the treated lesion and describe the marrow-stimulation technique.
Report this code for cartilage-restoration work, not routine cartilage smoothing alone; smoothing or debridement at the treated site is included. The operative report should distinguish this work from drilling for an osteochondritis dissecans lesion and document laterality, lesion location, and technique. CMS assigns a 90-day global period, including the day-before preoperative visit and related postoperative care through day 90. When related knee endoscopies are performed together, CMS endoscopy-family pricing applies. Modifier 50 identifies bilateral performance and CMS pays at 150%. Assistant-at-surgery payment requires documented medical necessity; co-surgeons and team surgery are 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.
29879 in Hawaii, Guam
| Payment locality | Office | Facility |
|---|---|---|
| Hawaii, Guam | Unavailable | $634.60 |
How the 29879 rate is calculated
Each of 29879’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 · 29879
RVUs × geographic indexes × conversion factor
Work8.77
8.77 RVUs× 1.000 GPCI
Practice expense8.07
8.07 RVUs× 1.000 GPCI
Malpractice1.82
1.82 RVUs× 1.000 GPCI
Adjusted RVUs
18.6600
Conversion factor
$33.4009
Medicare rate
$623.26
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 29879
29879 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 29879
Arthroscopic cartilage procedure
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 090 | Major surgery: the day before, the day of, and 90 days after are included. |
| Multiple procedures | 3 | Endoscopy family rules apply. |
| Bilateral (modifier 50) | 1 | Bilateral with modifier 50 pays 150% of the fee schedule amount. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
| Split (54/55/56) | 0.10/0.69/0.21 | Share of the payment for pre-op, the procedure itself, and post-op care. |
Global surgery period · 29879
Arthroscopic cartilage procedure
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.
Pre-op dayGlobal period
What modifiers do to the payment
Modifier 50 · payment effect
With and without the modifier
29879 without 50 · national facility
$623.26
Arthroscopic cartilage procedure
29879-50 · Bilateral: 150%
$934.89
Both sides on one line with modifier 50 are paid at 150% of the fee schedule amount (subject to multiple-procedure rules with other procedures).
29879 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 29877Knee chondroplasty
- Choose 29879 when the surgeon abrades or perforates subchondral bone to stimulate repair. Choose 29877 for debridement or shaving without that work; chondroplasty at the 29879 treatment site is included.
- 29885Knee arthroscopy
- 29885 addresses arthroscopic drilling for an osteochondritis dissecans lesion. Code 29879 is for abrasion or marrow stimulation of a cartilage defect.
- 29870Knee arthroscopy
- 29870 is for diagnostic knee arthroscopy without the surgical cartilage-restoration work reported with 29879.
29879 billing questions
How does 29879 differ from 29877?
29879 involves preparing subchondral bone with abrasion, drilling, or microfracture to stimulate repair. Use 29877 for arthroscopic debridement or shaving without that marrow-stimulation work.
Can 29877 be reported for chondroplasty performed at the same lesion?
No. Chondroplasty or smoothing at the site treated with 29879 is included in the cartilage-restoration service.
What documentation supports 29879?
Document the treated cartilage defect, its knee location and laterality, and the abrasion, drilling, or microfracture technique performed.
How is bilateral performance reported?
Report modifier 50 for bilateral performance; CMS pays the bilateral procedure at 150%.
How does payment work when other knee arthroscopies are performed in the same session?
CMS applies endoscopy-family pricing when related endoscopies are performed together. The operative report should support each distinct procedure performed.
Can an assistant or another surgeon be reported?
Assistant-at-surgery payment requires documentation of medical necessity. CMS does not permit co-surgeons or team surgery for this code.
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
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