CPT code 28050: Joint biopsy, foot joint lining2026 Medicare rate & RVUs in Illinois
Report this procedure when a surgeon samples the lining of a foot joint for diagnostic evaluation rather than removing the lining therapeutically.
Medicare pays $392.20–$425.42 for 28050 in the office in Illinois, from Rest of Illinois to Chicago, IL. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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On this page 9 sections
What 28050 covers
A surgeon obtains tissue from the lining of a foot joint so it can be examined for causes of joint disease, such as unexplained inflammation or suspected infection. Orthopedic surgeons and podiatrists may perform the biopsy in an operating room or another surgical setting. The sampled tissue may be sent for pathology or other appropriate testing. This service concerns a foot joint; a biopsy of a toe joint is represented separately.
Select the code based on the documented joint and the procedure actually performed. The operative note should identify the foot joint, the tissue sampled, and the diagnostic purpose; a therapeutic removal of joint lining is a different service. This code has a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. When multiple procedures are performed in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. For bilateral reporting, modifier 50 is paid at 150%. Medicare does not pay an assistant at surgery; co-surgeons require 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 28050 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
4 payment localities
$392.20 to $425.42
| Payment locality | Office | Facility |
|---|---|---|
| Chicago, IL | $425.42 | $280.74 |
| East St. Louis, IL | $399.54 | $267.10 |
| Rest of Illinois | $392.20 | $260.77 |
| Suburban Chicago, IL | $424.50 | $276.65 |
How the 28050 rate is calculated
Each of 28050’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 · 28050
RVUs × geographic indexes × conversion factor
Work4.28
4.28 RVUs× 1.000 GPCI
Practice expense7.54
7.54 RVUs× 1.000 GPCI
Malpractice0.37
0.37 RVUs× 1.000 GPCI
Adjusted RVUs
12.1900
Conversion factor
$33.4009
Medicare rate
$407.16
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 28050
28050 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 28050
Joint biopsy, foot joint lining
| 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) | 1 | Not paid (statutory restriction). |
| 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 · 28050
Joint biopsy, foot joint lining
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
28050 without 50 · national office
$407.16
Joint biopsy, foot joint lining
28050-50 · Bilateral: 150%
$610.74
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).
28050 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 28054Joint biopsyToe joint lining
- Choose 28054 when the biopsied joint is in a toe. This code is for a foot joint.
- 28020Foot joint arthrotomyIntertarsal or tarsometatarsal
- This code represents sampling joint lining for diagnostic evaluation; 28020 represents exploration of a foot joint.
- 28070Foot synovectomyTarsometatarsal joint
- A biopsy obtains tissue for evaluation. 28070 describes removal of foot joint lining as a therapeutic procedure.
28050 billing questions
How is a foot joint biopsy different from a toe joint biopsy?
This code is for sampling the lining of a foot joint. Use the separate toe-joint biopsy code, 28054, when the sampled joint is in a toe.
Can the surgeon also report a synovectomy?
A diagnostic tissue sample is distinct from therapeutic removal of joint lining. Report a separate synovectomy only when it is independently performed and documented, rather than treating the biopsy itself as a synovectomy.
Does joint exploration include a biopsy?
Exploration codes describe inspection or exploration of a joint, while this code represents obtaining tissue from the joint lining. The operative note should support each service reported.
What should the operative note document?
Document the specific foot joint, the tissue sampled, and the diagnostic reason for obtaining the specimen. The record should make clear that tissue was sampled rather than the lining being removed therapeutically.
How does Medicare handle bilateral reporting and multiple procedures?
Modifier 50 is subject to the bilateral payment rule of 150%. When multiple procedures occur in the same session, the highest-valued procedure is paid in full and the others are reduced to 50%.
Can an assistant or co-surgeon be reported?
Medicare does not pay an assistant at surgery for this code. Co-surgeon payment requires supporting documentation; 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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