Billing code 27438: Patellar arthroplastyMedicare rate & RVUs in Oklahoma
Reports surgical replacement or resurfacing of the patella with a prosthetic implant when the procedure is limited to the kneecap rather than a total knee replacement.
CMS doesn’t publish an office rate for 27438 in Oklahoma.
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 27438 covers
An orthopedic surgeon replaces or resurfaces the joint-facing surface of the patella with a prosthetic implant. The procedure addresses patellar joint damage when the operative plan is for patellar arthroplasty, rather than replacement of the full knee joint. It is performed in an operating room, typically in a hospital or ambulatory surgery center. The operative report should identify the patellar procedure and the use of a prosthetic component.
Report this code for the patellar arthroplasty itself; patellar resurfacing performed as part of a total knee arthroplasty is included in that broader procedure. The service has a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. For multiple procedures in the same session, the highest-valued procedure is paid in full and others at 50%. When performed bilaterally with modifier 50, payment is at 150%. Assistant-at-surgery payment may be available; 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.
27438 in Oklahoma
| Payment locality | Office | Facility |
|---|---|---|
| Oklahoma | Unavailable | $730.26 |
How the 27438 rate is calculated
Each of 27438’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 · 27438
RVUs × geographic indexes × conversion factor
Swap in your local Medicare rate.
Work 11.59Practice expense 9.39Malpractice 2.43
All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.
Payment rules and modifiers for 27438
27438 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 27438
Patellar arthroplasty
| 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 · 27438
Patellar arthroplasty
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
27438 without 50 · national facility
$781.92
Patellar arthroplasty
27438-50 · Bilateral: 150%
$1,172.88
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).
27438 compared with similar codes
Compare codes
27438 vs 27437 vs 27447 vs 27424: national Medicare rates
Swap in your local Medicare rate.
How to choose
- 27437Patellar arthroplasty
- Use 27438 when the patellar arthroplasty includes a prosthetic implant. Use 27437 when the patellar arthroplasty is performed without one.
- 27447Total knee replacement
- Use 27447 for total knee arthroplasty. Do not separately report 27438 for patellar resurfacing performed as part of that replacement.
- 27424Patella surgery
- This code is for patellar arthroplasty with a prosthetic implant. Code 27424 describes patellar removal rather than implant replacement.
27438 billing questions
How is this different from 27437?
This code includes a prosthetic implant for the patella. Code 27437 is the corresponding patellar arthroplasty without a prosthesis.
Can this be reported separately with total knee arthroplasty?
No. Patellar resurfacing performed as part of total knee arthroplasty is included in the broader procedure; do not separately report this code for that work.
What documentation supports reporting this code?
The operative report should describe the patellar arthroplasty and identify the prosthetic component. It should also make clear whether the service was a standalone patellar procedure or part of a broader knee replacement.
How does the 90-day global period affect postoperative care?
The day-before preoperative visit and 90 days of related postoperative care are included in the global period.
How are bilateral procedures and multiple procedures in one session handled?
A bilateral procedure reported with modifier 50 is paid at 150%. For multiple procedures in the same session, the highest-valued procedure is paid in full and others at 50%.
Can an assistant or co-surgeon be reported?
Assistant-at-surgery payment may be available. 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
Fee sheets
Put 27438 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 →