Billing code 29870: Knee arthroscopyMedicare rate & RVUs in Washington
Reports arthroscopic inspection of the knee for diagnostic purposes, including an optional synovial biopsy when tissue sampling is part of the evaluation.
Medicare pays $618.03–$695.72 for 29870 in the office in Washington, from Rest Of Washington to Seattle (King Cnty). 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.
On this page 9 sections
What 29870 covers
The orthopedic surgeon examines the knee joint through an arthroscope to evaluate an unresolved problem, such as persistent pain or suspected intra-articular disease. The surgeon may also take a synovial tissue sample for laboratory examination. This service is typically performed in an operating room or ambulatory surgery setting when imaging, examination, or other evaluation has not established the diagnosis.
Select this code when the arthroscopy is diagnostic, with or without synovial biopsy, rather than a therapeutic arthroscopic procedure. The operative report should support the diagnostic purpose, document the areas examined and findings, and describe any biopsy. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. For multiple procedures in one session, the highest-valued procedure is paid in full and others at 50%. Bilateral reporting with modifier 50 is paid at 150%. Assistant-at-surgery payment is restricted; co-surgeons are paid only with 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 29870 pays more and less in Washington
| Payment locality | Office | Facility |
|---|---|---|
| Rest Of Washington | $618.03 | $404.19 |
| Seattle (King Cnty) | $695.72 | $446.55 |
How the 29870 rate is calculated
Each of 29870’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 · 29870
RVUs × geographic indexes × conversion factor
Work5.06
5.06 RVUs× 1.000 GPCI
Practice expense11.96
11.96 RVUs× 1.000 GPCI
Malpractice1.03
1.03 RVUs× 1.000 GPCI
Adjusted RVUs
18.0500
Conversion factor
$33.4009
Medicare rate
$602.89
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 29870
29870 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 29870
Knee arthroscopy
| 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 · 29870
Knee arthroscopy
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
29870 without 50 · national office
$602.89
Knee arthroscopy
29870-50 · Bilateral: 150%
$904.34
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).
29870 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 29871Knee arthroscopy
- 29870 is diagnostic, with optional synovial biopsy. 29871 describes arthroscopy performed to treat infection in the knee.
- 29875Knee synovectomy
- 29875 is for limited synovectomy, which removes synovial tissue as treatment. A biopsy taken during diagnostic inspection remains within 29870.
- 29876Knee synovectomy
- 29876 describes major synovectomy involving extensive synovial removal, not diagnostic inspection or tissue sampling alone.
- 29881Knee meniscectomy
- 29881 reports arthroscopic meniscectomy in one compartment. When that treatment is performed, the diagnostic inspection of the same knee is generally integral.
29870 billing questions
When should 29870 be chosen instead of a therapeutic knee arthroscopy code?
Use 29870 when the surgeon performs diagnostic inspection, with or without synovial biopsy, rather than a procedure to treat a finding. If the surgeon performs a definitive arthroscopic intervention in the same knee, report the therapeutic procedure rather than separately reporting the diagnostic inspection.
Is synovial biopsy included in 29870?
Yes. The code includes diagnostic knee arthroscopy whether or not the surgeon takes a synovial biopsy. A separately performed laboratory examination of the tissue may be reported by the appropriate laboratory provider.
Can 29870 be reported with a knee meniscectomy performed during the same session?
The diagnostic inspection is generally integral when the surgeon proceeds to a therapeutic arthroscopy in the same knee. Report the code for the meniscectomy, such as 29881 for a single-compartment meniscectomy, rather than separately reporting 29870.
How does the 90-day global period affect billing?
The global period includes the day-before preoperative visit and 90 days of related postoperative care. CMS applies this period to 29870.
How is bilateral 29870 reported under the CMS facts?
When the procedure is performed on both knees, report modifier 50; CMS pays the bilateral procedure at 150%.
Can an assistant or co-surgeon be paid for 29870?
CMS restricts assistant-at-surgery payment for this code. Co-surgeons are paid only when supporting documentation is provided; 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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