FeeBase
Log inGet started
Menu

Billing code 27330: Knee biopsyMedicare rate & RVUs

Open knee-joint biopsy code for obtaining synovial lining tissue when persistent synovitis or another intra-articular abnormality requires tissue diagnosis.

CMS RVU26DEffective Oct 1, 2026109 payment localities77 Medicare services in 2024

Medicare pays $412.84 for 27330 nationally in a facility.

Medicare rate · 27330

Knee biopsy

Work RVUs
4.98
Total RVUs
12.36
Global days
090

National rate · 2026

$412.84

Facility setting, before claim adjustments.

See every locality for 27330 →Billed by an NP, PA or therapist? →

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 10 sections
  1. Medicare rate
  2. What 27330 covers
  3. By payment locality
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Similar codes
  8. Related codes
  9. Billing questions
  10. Sources

What 27330 covers

27330 represents open entry into the knee joint to obtain a sample of the synovial lining for diagnostic evaluation. An orthopedic surgeon may perform it when persistent, unexplained synovitis or another abnormal joint-lining change requires tissue examination, including evaluation for inflammatory or infectious disease. The specimen may be sent for histology or other laboratory analysis. This is an open biopsy, not an arthroscopic sampling procedure or removal of the joint lining.

Report the code when the operative service includes an arthrotomy to take a biopsy; the operative note should identify the knee, the abnormal tissue sampled, and the biopsy performed. The 90-day global period includes the day-before preoperative visit and 90 days of related postoperative care. When multiple procedures are performed in one session, the highest-valued procedure is paid in full and other procedures receive the standard multiple-procedure reduction. For bilateral procedures, modifier 50 is paid at 150%. Assistant-at-surgery payment is restricted, 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 27330 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

27330 office and facility rates by payment locality
Payment localityOfficeFacility
AlabamaUnavailable$370.98
Alaska*Unavailable$493.66
ArizonaUnavailable$401.16
ArkansasUnavailable$365.78
AtlantaUnavailable$423.89
AustinUnavailable$421.32
BakersfieldUnavailable$422.25
Baltimore/Surr. CntysUnavailable$439.35
BeaumontUnavailable$391.33
BrazoriaUnavailable$404.41

27330 rates by state

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

MEWIVTNHMTNDMNMINYMARIWAIDWYSDIAILINOHPANJCTORNVUTCONEMOKYWVVAMDDECAAZNMKSOKARTNNCSCDCTXLAMSALGAFLAKHI

Explore a state

Local rates. Clear comparisons.

Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.

View every state and territory as a table
27330 office rate range by state
State / territoryOffice rate rangeLocalities
AKNo published base rate1
ALNo published base rate1
ARNo published base rate1
AZNo published base rate1
CANo published base rate29
CONo published base rate1
CTNo published base rate1
DCNo published base rate1
DENo published base rate1
FLNo published base rate3
GANo published base rate2
GUNo published base rate1
HINo published base rate1
IANo published base rate1
IDNo published base rate1
ILNo published base rate4
INNo published base rate1
KSNo published base rate1
KYNo published base rate1
LANo published base rate2
MANo published base rate2
MDNo published base rate3
MENo published base rate2
MINo published base rate2
MNNo published base rate1
MONo published base rate3
MSNo published base rate1
MTNo published base rate1
NCNo published base rate1
NDNo published base rate1
NENo published base rate1
NHNo published base rate1
NJNo published base rate2
NMNo published base rate1
NVNo published base rate1
NYNo published base rate5
OHNo published base rate1
OKNo published base rate1
ORNo published base rate2
PANo published base rate2
PRNo published base rate1
RINo published base rate1
SCNo published base rate1
SDNo published base rate1
TNNo published base rate1
TXNo published base rate8
UTNo published base rate1
VANo published base rate2
VINo published base rate1
VTNo published base rate1
WANo published base rate2
WINo published base rate1
WVNo published base rate1
WYNo published base rate1

How the 27330 rate is calculated

Each of 27330’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 · 27330

RVUs × geographic indexes × conversion factor

Work4.98

4.98 RVUs× 1.000 GPCI

Practice expense6.31

6.31 RVUs× 1.000 GPCI

Malpractice1.07

1.07 RVUs× 1.000 GPCI

Adjusted RVUs

12.3600

Conversion factor

$33.4009

Medicare rate

$412.84

Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.

Payment rules and modifiers for 27330

27330 has a 90-day global period: related visits in that window are included in the surgery payment.

CMS payment indicators · 27330

Knee biopsy

RuleCMS valueWhat it means
Global period090Major surgery: the day before, the day of, and 90 days after are included.
Multiple procedures2Standard reduction: highest-valued procedure at 100%, others at 50%.
Bilateral (modifier 50)1Bilateral with modifier 50 pays 150% of the fee schedule amount.
Assistant at surgery (80/81/82/AS)1Not paid (statutory restriction).
Co-surgeons (62)1Permitted with supporting documentation.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.
Split (54/55/56)0.10/0.69/0.21Share of the payment for pre-op, the procedure itself, and post-op care.

Global surgery period · 27330

Knee biopsy

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.

  • 24Unrelated E/M visit by the same physician
  • 79Unrelated procedure (starts its own global period)
  • 58Staged, more extensive, or therapy procedure that was planned
  • 78Unplanned return to the operating room for a related complication
SurgeryVisit
Sep 23, 2026Jan 10, 2027

Pre-op dayGlobal period

What modifiers do to the payment

Modifier 50 · payment effect

With and without the modifier

27330 without 50 · national facility

$412.84

Knee biopsy

27330-50 · Bilateral: 150%

$619.26

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).

When to use modifier 50

27330 compared with similar codes

Compare codes · National

4 codes, side by side

  • 27330

    Knee biopsy4.98 wRVU

    Not priced

  • 29870

    Knee arthroscopy5.06 wRVU

    $602.89

  • 27331

    Knee arthrotomy5.87 wRVU

    Not priced

  • 27334

    Knee synovectomy8.96 wRVU

    Not priced

How to choose

29870Knee arthroscopy
27330 describes an open arthrotomy biopsy. Use the arthroscopy code when the surgeon obtains the synovial sample through an arthroscope.
27331Knee arthrotomy
27330 is reported for open tissue sampling. 27331 describes an open knee procedure directed to exploration, drainage, or foreign-body removal.
27334Knee synovectomy
27330 removes a sample for diagnosis; 27334 is for open synovectomy, in which synovial tissue is removed therapeutically.

Codes related to 27330

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

Codes related to 27330
CodeHow it relatesNational office range
Used instead
29870Knee arthroscopyArthroscopic diagnostic knee service may apply when synovial tissue is sampled arthroscopically.$529.87–$782.08
27331Knee arthrotomyOpen knee arthrotomy for exploration, drainage, or foreign-body removal rather than biopsy.No office rate
27334Knee synovectomyOpen knee synovectomy removes synovial tissue rather than sampling it for diagnosis.No office rate
27335Knee synovectomyOpen knee synovectomy involving a broader extent of lining removal, not a diagnostic biopsy.No office rate

27330 billing questions

When should 27330 be chosen instead of an arthroscopic knee biopsy?

Use 27330 for an open arthrotomy performed to sample the knee lining. When the biopsy is obtained arthroscopically, consider the applicable arthroscopy code, such as 29870.

Does 27330 include the pathology examination?

The code represents obtaining the tissue through the open procedure. Histologic examination is a separate laboratory service when performed and reportable by the pathology provider.

What documentation supports reporting 27330?

Document the knee side, the reason tissue diagnosis was needed, the synovial or other intra-articular tissue sampled, and the open biopsy performed.

Can 27330 be reported bilaterally?

For a bilateral procedure, CMS pays 150% when modifier 50 is reported. The operative documentation should support biopsy of both knees.

How does the global period affect postoperative visits?

27330 has a 90-day global period. The day-before preoperative visit and 90 days of related postoperative care are included.

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
RVUs for 27330PPRRVU2026_Oct_nonQPP.csv, line 2,841 (RVU26D)

Open CMS sourceHow we calculate rates

Did this answer your question about what 27330 pays?

Tell us what you were actually trying to work out. We’ll answer you directly, or build the page that does.

Fee sheets

Put 27330 and the rest of your codes on one sheet

Build a fee sheet from your own code list at your locality, put your payer contracts beside Medicare, and see what changed each quarter.

Build my fee sheetOr price your code list free →