Arthroscopy · Knee

Arthroscopic knee surgery involving limited removal or resection of synovial tissue from one compartment of the knee joint.

Verified May 8, 2026 · 6 sources ↓

Medicare: $474.29
Total RVUs: 14.2
Global, days: 90
Region: Knee

Drawn from CMSAAPCPriority HealthTexas DWC

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 compartment(s) the synovectomy was performed in (medial, lateral, or patellofemoral) — 'limited synovectomy' without compartment identification triggers audit flags.
Establish pathologic synovial disease by diagnosis: pigmented villonodular synovitis, inflammatory arthropathy, or similar — not 'synovial cleanup' or 'fibrillating synovium.'
Confirm no other arthroscopic knee procedure was performed on the same knee at the same encounter; if any was, 29875 cannot be billed separately.
Document affected side (right or left) explicitly in both the operative note and the diagnosis line to support laterality modifiers.
Record conservative treatment failure and medical necessity supporting isolated synovectomy as the indicated procedure.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 58 Staged or related 59 Distinct service 73 Discontinued pre-anesthesia 74 Discontinued post-anesthesia 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 29875 describes a surgical knee arthroscopy in which the surgeon performs a limited synovectomy — partial resection of the synovial lining — within a single compartment. It is designated a 'separate procedure,' meaning it is only billable when performed as a standalone service. The moment any other arthroscopic knee procedure is performed on the same knee at the same encounter, 29875 is bundled into that procedure under NCCI rules and cannot be reported separately, regardless of compartment location.

To distinguish 29875 from the more extensive 29876 (major synovectomy, two or three compartments): 29875 covers a single-compartment resection performed for pathologic synovial disease — not incidental joint cleanup. Documentation must establish that the synovitis is a distinct pathologic finding, not routine debridement. Payers routinely deny 29875 when operative notes describe the synovectomy as 'cleaning up' loose synovium without naming a pathologic diagnosis.

The 90-day global period applies. If a complication or unrelated procedure is performed on the same knee within 90 days, append modifier 78 (unplanned return, related) or 79 (unrelated procedure) as appropriate. Laterality modifiers LT and RT are required for all payers; missing laterality is a top-line claim edit failure.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	6.29
Practice expense RVU	6.6
Malpractice RVU	1.31
Total RVU	14.2
Medicare national rate	$474.29
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	$474.29
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 29875 get rejected.

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

NCCI bundle with any other ipsilateral arthroscopic knee code (29877, 29880, 29881, etc.) — 29875 is integral to all of them and cannot be unbundled.
Operative note describes synovectomy as routine joint cleanup or debridement rather than treatment of documented pathologic synovial disease.
Missing or incorrect laterality modifier — payers require LT or RT; absence triggers automatic claim edit failure.
Modifier 59 appended in an attempt to unbundle from a same-session arthroscopic procedure — NCCI policy manual explicitly prohibits separate reporting of 29875 with any other ipsilateral knee arthroscopy code, even with modifier 59.
Medical necessity not established — no ICD-10 diagnosis code reflecting pathologic synovitis linked to the claim.

Frequently asked questions

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

01Can 29875 be billed with 29881 on the same knee, same day?

No. The NCCI policy manual states 29875 shall not be reported with any other arthroscopic knee procedure on the ipsilateral knee. Modifier 59 does not override this edit. The limited synovectomy is considered integral to 29881.

02What is the difference between 29875 and 29876?

29875 covers limited synovectomy in one compartment and is a 'separate procedure' — only billable standalone. 29876 covers major synovectomy across two or three compartments and has its own bundling rules; it may be reported with some arthroscopic procedures when no other procedure is performed in those compartments.

03Does a 90-day global period apply to 29875?

Yes. The 90-day global covers the operative day and all routine post-op care through day 90. Unrelated procedures in that window require modifier 79; a return for a related complication requires modifier 78.

04Is 29875 ever the right code when synovectomy is done alongside another knee arthroscopy in a different compartment?

No — not for Medicare or payers following NCCI. The rule is absolute: any other ipsilateral arthroscopic knee procedure bundles 29875. If the synovectomy work is in a truly separate compartment, evaluate whether G0289 applies instead, but confirm payer-specific policy before substituting.

05What ICD-10 diagnoses support medical necessity for standalone 29875?

Pathologic synovial disease diagnoses carry the claim: pigmented villonodular synovitis (M12.2x1/M12.2x2), synovial chondromatosis (M67.2x-), or inflammatory arthropathy with documented synovitis. Non-specific or degenerative arthritis codes alone are weak; document clinical correlation explicitly.

06Where is 29875 typically performed, and does site of service affect payment?

29875 is performed in an ASC or hospital outpatient department (HOPD). Medicare pays the facility at different rates for each setting — see the Site of Service comparison table on this page. Physician work RVUs are the same regardless of setting.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

01CMS Physician Fee Schedule 2026
02CMS NCCI Policy Manual for Medicare Services, Chapter 4 (2024) — https://www.cms.gov/files/document/medicare-ncci-policy-manual-2024-chapter-4.pdf
03AAPC Knowledge Center: Reinforce Knee Arthroscopy Coding — https://www.aapc.com/blog/33738-33738/
04Priority Health Billing Policy No. 125: Knee Arthroscopy — https://priorityhealth.stylelabs.cloud/api/public/content/e8ffaccadd6c4927ae3159cd9fe868df?v=022380ae
05Texas DWC Medical Fee Dispute Resolution, CPT 29875 — https://www.tdi.texas.gov/medcases/medfee19/m4191431.pdf
06CMS Medical Policy Article A52369: Arthroscopic Lavage and Debridement for the Osteoarthritic Knee — https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=52369&ver=11&

Mira AI Scribe

Mira's AI scribe captures the specific compartment treated, the pathologic diagnosis driving the synovectomy, and explicit laterality from the surgeon's dictation. It flags in real time if any other arthroscopic knee procedure appears in the same encounter note — the scenario that triggers automatic NCCI bundling and makes 29875 non-billable. This prevents post-submission denials that require appeal cycles to resolve.

See how Mira captures CPT 29875 documentation