CPT code 27334: Knee synovectomy, anterior or posterior approach2026 Medicare rate & RVUs

Medicare pays $649.98 for 27334 nationally in a facility.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

What 27334 covers

This code represents an open knee arthrotomy with removal of diseased synovial tissue through an anterior or posterior approach. Orthopedic surgeons typically perform it in an operating room for substantial synovial disease, such as persistent inflammatory or proliferative synovitis requiring surgical removal rather than a diagnostic tissue sample. The operative report should identify the approach and describe the synovectomy performed; extension into the popliteal area points to the more extensive sibling code, 27335.

Report 27334 for the open synovectomy described, not for synovial biopsy alone or arthroscopic synovectomy. Documentation should establish the knee site, open approach, tissue removed, and extent of the procedure. CMS assigns a 90-day global period: the day-before preoperative visit and 90 days of related postoperative care are included. For multiple procedures in the same session, the highest-valued procedure is paid in full and others at 50%. Bilateral reporting with modifier 50 is paid at 150%. An assistant at surgery may be paid; co-surgeon payment requires supporting documentation, and team surgery is 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.

Where 27334 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

27334 rates by state

Office rate range in each state. Select a state to see its payment localities.

How the 27334 rate is calculated

Each of 27334’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.

Payment rules and modifiers for 27334

27334 has a 90-day global period: related visits in that window are included in the surgery payment.

What modifiers do to the payment

When to use modifier 50

27334 compared with similar codes

How to choose

27335Knee synovectomyAnterior and posterior

Both describe open knee synovectomy, but 27335 includes the popliteal area. Use 27334 for the anterior or posterior approach without that extent.

27330Knee biopsyOpen synovial tissue sampling

27330 is for sampling knee synovium for biopsy; 27334 involves open surgical removal of diseased synovial tissue.

29876Knee synovectomyTwo or more compartments

29876 describes arthroscopic major synovectomy in two or more compartments. Code 27334 is an open procedure through arthrotomy.

27331Knee arthrotomyAnterior or posterior synovectomy

27331 describes open knee exploration or treatment, not the synovectomy represented by 27334. The operative work documented determines the code.

Codes related to 27334

Related codes aren’t interchangeable: bill the code that matches the service performed.

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

Open CMS sourceHow we calculate rates