CPT code 38531: Groin node surgery, open inguinofemoral nodes2026 Medicare rate & RVUs in California

CMS doesn’t publish an office rate for 38531 in California.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

What 38531 covers

The surgeon makes an incision in the groin to obtain or remove one or more inguinofemoral lymph nodes for diagnostic evaluation or staging. Typical situations include sampling a suspicious groin node or a mapped node during evaluation of vulvar or skin malignancy. General, gynecologic, and surgical oncologists commonly perform the procedure in an operating room. This code represents open node sampling or excision, rather than removal of an entire nodal basin.

Choose the code based on the open approach and inguinofemoral location. The operative report should identify the groin nodal basin and describe the nodes sampled or removed and the reason for the procedure. CMS assigns 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 the others at 50%. Bilateral reporting with modifier 50 is paid at 150%. An assistant at surgery is paid only when medical necessity is documented; co-surgeons and team surgery are 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 38531 pays more and less in California

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

29 of 29 payment localities

How the 38531 rate is calculated

Each of 38531’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.

Payment rules and modifiers for 38531

38531 has a 90-day global period: related visits in that window are included in the surgery payment.

What modifiers do to the payment

When to use modifier 50

38531 compared with similar codes

How to choose

38500Lymph node biopsyOpen, superficial node

Both describe open node sampling or removal, but 38531 is specific to inguinofemoral nodes; 38500 applies to superficial nodes at other sites.

38505Lymph node biopsyNeedle, superficial node

Use 38505 for needle sampling of a lymph node. Use 38531 when the surgeon obtains or removes the groin node through an open approach.

38760Groin lymphadenectomySuperficial, includes Cloquet's node

Code 38760 describes a superficial inguinal lymphadenectomy, a broader nodal dissection. Code 38531 describes open sampling or excision of inguinofemoral nodes.

Codes related to 38531

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

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

Open CMS sourceHow we calculate rates