Arthroscopy · Knee

Knee arthroscopy with major synovectomy involving two or more compartments for pathologic synovial disease

Verified May 8, 2026 · 7 sources ↓

Medicare: $614.91
Total RVUs: 18.41
Global, days: 90
Region: Knee

Drawn from CMSAAPCOutsourcestrategiesAAOS

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 7 cited references ↓

Name each compartment where synovectomy was performed (medial tibiofemoral, lateral tibiofemoral, patellofemoral) — two or more required
Document pathologic synovial disease as the indication, not incidental cleanup of fibrillating synovium during another procedure
If billing with a second arthroscopic knee code, confirm in the operative note that the synovectomy compartments are distinct from compartments where the other procedure was performed
Preoperative imaging or prior conservative treatment records supporting medical necessity for synovectomy
Operative note must specify the extent of synovial resection, not just note its presence
Diagnosis coding must reflect the underlying pathology driving the synovectomy (e.g., inflammatory arthritis, synovitis) — not isolated osteoarthritis if NCD 150.9 applies

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 51 Multiple procedures 57 Decision for surgery 58 Staged or related 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 29876 describes an arthroscopic knee procedure in which diseased synovial tissue is resected from two or more compartments of the knee joint — for example, the medial tibiofemoral, lateral tibiofemoral, or patellofemoral compartments. This is not routine joint cleanup; the code requires documented pathologic synovial disease, not incidental synovium trimming performed in the course of another procedure.

The critical bundling rule comes from the NCCI Policy Manual, Chapter 4: 29876 can be reported alongside another ipsilateral knee arthroscopy only if the synovectomy is performed in two compartments where no other arthroscopic procedure is being performed. If you're billing 29876 with 29880 (medial and lateral meniscectomy), the edit sticks — 29880 already occupies both tibiofemoral compartments, leaving no qualifying compartments for the synovectomy.

CMS NCD 150.9 is the coverage ceiling for osteoarthritic knees specifically: arthroscopic lavage and debridement for osteoarthritis are non-covered, and payers will scrutinize 29876 claims where the primary diagnosis is osteoarthritis without a separate pathologic synovial indication. The 90-day global period applies; post-op visits, wound care, and related care are bundled through day 90.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	8.65
Practice expense RVU	7.99
Malpractice RVU	1.77
Total RVU	18.41
Medicare national rate	$614.91
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	$614.91
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 29876 get rejected.

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

Bundled into a co-billed arthroscopic procedure when both share the same two knee compartments — NCCI edit not bypassable in that scenario
Medical necessity denied when primary diagnosis is osteoarthritis without a documented pathologic synovial condition distinct from degenerative joint disease, per NCD 150.9
Operative note describes synovial cleanup incidental to a more extensive procedure rather than a targeted resection for pathologic disease
Missing compartment-specific documentation — note says 'synovectomy performed' without identifying which two or more compartments
Global period conflict: follow-up visit billed without modifier 24 when the visit falls within the 90-day global

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01Can I bill 29876 with 29880 on the same knee?

No. Per NCCI Chapter 4, 29880 covers both tibiofemoral compartments, leaving no compartment where the synovectomy qualifies as separately reportable. The edit is not bypassable with modifier 59 in this pairing.

02What compartment documentation does 29876 actually require?

You must identify at least two named compartments (medial tibiofemoral, lateral tibiofemoral, patellofemoral) where pathologic synovial resection was performed. Vague language like 'synovitis addressed throughout' won't support the claim on audit.

03Can 29876 be billed for an osteoarthritic knee?

CMS NCD 150.9 excludes arthroscopic lavage and debridement for osteoarthritis. If the synovectomy is performed for a discrete pathologic synovial process — not as treatment of OA itself — it may be supportable, but diagnosis coding and documentation must clearly reflect that distinction. Expect scrutiny.

04How does the NCCI rule differ from CPT guidelines on billing 29876 with another arthroscopic knee code?

CPT allows 29876 with another knee arthroscopy whenever pathologic synovial disease is documented, even in the same compartment (with limited exclusions). Medicare's NCCI adds a second requirement: the synovectomy must occur in compartments where no other arthroscopic procedure is performed. For Medicare patients, the NCCI rule controls.

05Does modifier 59 override the NCCI bundle when 29876 is billed with 29880?

No. The NCCI logic here isn't about separate anatomic sites or encounters — it's that 29880 already accounts for both tibiofemoral compartments. Appending 59 or XS doesn't create a billing rationale when no qualifying distinct compartment exists.

06What modifier applies if the surgeon decides during a same-day E/M to proceed with arthroscopic synovectomy?

Append modifier 57 to the E/M code when the decision for this 90-day global procedure is made the day of or day before surgery. That prevents the E/M from being absorbed into the global preoperative period.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures compartment-by-compartment synovectomy documentation from dictation — recording which compartments received synovial resection and the pathologic indication driving each. That specificity prevents the most common 29876 denial: an operative note that mentions synovectomy in passing without establishing that two qualifying compartments were treated for documented synovial disease rather than routine joint cleanup.

See how Mira captures CPT 29876 documentation