Billing code 27334: Knee synovectomyMedicare rate & RVUs in Oregon
Open knee synovectomy through an anterior or posterior arthrotomy to remove diseased synovium, without the popliteal-area extent represented by its sibling code.
CMS doesn’t publish an office rate for 27334 in Oregon.
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 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 in Oregon
| Payment locality | Office | Facility |
|---|---|---|
| Portland | Unavailable | $670.41 |
| Rest Of Oregon | Unavailable | $629.98 |
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.
How the rate is built · 27334
RVUs × geographic indexes × conversion factor
Work8.96
8.96 RVUs× 1.000 GPCI
Practice expense8.60
8.60 RVUs× 1.000 GPCI
Malpractice1.90
1.90 RVUs× 1.000 GPCI
Adjusted RVUs
19.4600
Conversion factor
$33.4009
Medicare rate
$649.98
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 27334
27334 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 27334
Knee synovectomy
| 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 | 2 | Standard reduction: highest-valued procedure at 100%, others at 50%. |
| Bilateral (modifier 50) | 1 | Bilateral with modifier 50 pays 150% of the fee schedule amount. |
| Assistant at surgery (80/81/82/AS) | 2 | Paid. |
| Co-surgeons (62) | 1 | Permitted with supporting documentation. |
| 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 · 27334
Knee synovectomy
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
27334 without 50 · national facility
$649.98
Knee synovectomy
27334-50 · Bilateral: 150%
$974.97
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).
27334 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 27335Knee synovectomy
- Both describe open knee synovectomy, but 27335 includes the popliteal area. Use 27334 for the anterior or posterior approach without that extent.
- 27330Knee biopsy
- 27330 is for sampling knee synovium for biopsy; 27334 involves open surgical removal of diseased synovial tissue.
- 29876Knee synovectomy
- 29876 describes arthroscopic major synovectomy in two or more compartments. Code 27334 is an open procedure through arthrotomy.
- 27331Knee arthrotomy
- 27331 describes open knee exploration or treatment, not the synovectomy represented by 27334. The operative work documented determines the code.
27334 billing questions
When should 27335 be used instead?
Use 27335 when the open synovectomy includes the popliteal area. Code 27334 describes an anterior or posterior approach without that stated extent.
Can 27334 be reported for a synovial biopsy?
No. A biopsy of the knee joint lining is represented by 27330; 27334 is for open removal of diseased synovium.
How does arthroscopic synovectomy differ?
Codes 29875 and 29876 describe arthroscopic synovectomy, while 27334 is an open procedure through arthrotomy. The arthroscopic code depends on the extent performed.
What does the 90-day global period include?
The day-before preoperative visit and 90 days of related postoperative care are included in the global period for 27334.
How is bilateral surgery reported under the CMS facts?
Report bilateral surgery with modifier 50; CMS pays the bilateral procedure at 150%.
Can an assistant or co-surgeon be paid?
An assistant at surgery may be paid. Co-surgeons are paid only with supporting documentation, and team surgery is not permitted.
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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