CPT Code 36475: Endovenous RFA billing guide (2026)

CPT code 36475 is the billing code for endovenous radiofrequency ablation of an incompetent vein in an extremity, first vein treated.

The descriptor bundles all imaging guidance and monitoring, so neither is billed separately. Vascular surgeons, phlebologists, and interventional radiologists report it when they close a refluxing saphenous vein.

Medicare pays roughly $850 to $1,100 for the procedure in an office-based lab. In a hospital outpatient department or an ambulatory surgical center, it pays roughly $245 to $300. Wrong place of service, thin duplex ultrasound documentation, and modifier errors cause most denials. This guide covers the 2026 fee schedule, ICD-10 pairings, coverage criteria, modifiers, and the records payers expect.

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Key takeaways

CPT code 36475 covers radiofrequency ablation of the first incompetent vein, with all imaging guidance bundled in.

Medicare pays roughly $850 to $1,100 in an office-based lab and roughly $245 to $300 in a facility.

Add-on code 36476 reports each additional vein treated in the same session and is never billed alone.

The code carries a 000 global period, so only same-day related services are bundled into the payment.

A duplex ultrasound showing reflux, a conservative therapy log, and a signed operative note must all pre-date the claim.

CPT code 36475: Procedure description and clinical context

CPT code 36475 describes endovenous ablation therapy of an incompetent extremity vein using percutaneous radiofrequency energy. It applies to the first vein treated in a session. The AMA CPT code set gives the official descriptor. “Endovenous ablation therapy of incompetent vein, extremity, inclusive of all imaging guidance and monitoring, percutaneous, radiofrequency; first vein treated.”

The procedure targets venous insufficiency caused by reflux in the great saphenous vein, the small saphenous vein, or accessory tributaries. A radiofrequency catheter enters percutaneously under ultrasound guidance and is advanced to the target segment. Thermal energy is then applied to close the vessel.

Clinical indications include symptomatic varicose veins, chronic venous insufficiency, and venous reflux confirmed by duplex ultrasound. Reflux duration is typically 0.5 seconds or longer on standing. According to CMS Medicare Coverage Database article A52870, Medicare covers varicose vein treatment only after documented medical necessity and failed conservative therapy.

2026 fee schedule and Medicare reimbursement rates

Medicare physician fee schedule payment for CPT code 36475 depends on the setting. Non-facility rates apply in an office-based lab (OBL). Facility rates apply in a hospital outpatient department (HOPD) or an ambulatory surgical center. The difference between the two runs to several hundred dollars per procedure.

These figures are national averages. The facility range follows a total facility RVU of 7.38 at the 2026 conversion factor of $33.4009. Geographic payment localities then adjust the amount through the Geographic Practice Cost Index (GPCI). Verify the current figure for your Medicare Administrative Contractor (MAC) jurisdiction with the CMS Physician Fee Schedule lookup tool.

Rates change every year with the CMS Physician Fee Schedule Final Rule, so treat the amounts above as planning estimates.

Why the setting changes the payment

The non-facility rate is higher because the practice absorbs the overhead of the procedure room, the equipment, and the staff. In a HOPD or ASC the facility bills its own technical component, so CMS pays the physician only the professional component. For an OBL owner, the non-facility rate has to cover both clinical and facility costs. An OBL that bills POS 22 by mistake forfeits several hundred dollars on every procedure.

ICD-10 diagnosis codes that support the claim

Every CPT code 36475 claim needs a supporting ICD-10-CM diagnosis code, and laterality is mandatory. The ICD-10-CM code set carries separate codes for the right leg, the left leg, and an unspecified side. Reporting I83.90 when the record names the treated leg is a common denial trigger.

Code to the highest level of specificity the documentation supports. If the duplex report names the right great saphenous vein as the treated vessel, the diagnosis code has to carry that laterality. Dropping it when the chart supports it is a preventable denial.

Medicare coverage criteria and medical necessity requirements

Medicare covers CPT code 36475 under Local Coverage Determinations (LCDs) maintained by individual MACs, including Noridian and Novitas Solutions. Coverage is never automatic. Three criteria have to be met before a claim is approved, and the supporting records must pre-date the date of service.

• Duplex ultrasound confirmation: A duplex scan must show reflux of at least 0.5 seconds in the target vein on standing. The report has to sit in the medical record and pre-date the procedure.
• Conservative therapy failure: The patient must have tried and failed a course of conservative treatment. Most MACs want at least 6 weeks of graduated compression stocking use, and some LCDs specify 3 months. The record needs the duration, the stocking grade, and either adherence or the reason for failure.
• Physician attestation: The treating physician attests to medical necessity in the operative note. Symptoms have to be documented, including pain, heaviness, swelling, skin changes, or ulceration attributable to the reflux.

LCD criteria are MAC-specific. Noridian, Novitas, CGS, and Palmetto set slightly different thresholds for reflux duration and for conservative therapy. Check the applicable LCD for your jurisdiction before performing and billing the procedure.

Choosing the right place of service code

Place of Service (POS) is one of the most consequential fields on a 36475 claim. The wrong code either triggers an outright denial, or pays the facility rate on a service that earned the non-facility rate.

Noridian Medicare has published guidance confirming POS 11 for OBL settings and POS 22 for HOPD. Payer policy can differ where an OBL sits inside a hospital campus or attached to one. Verify with your MAC before billing.

Modifiers for CPT code 36475

Modifier selection affects both payment and NCCI compliance. The scenarios that come up most often are bilateral procedures, repeat sessions, and distinct procedural services.

For bilateral procedures, check whether your payer wants modifier 50 on a single line or two lines with RT and LT. Medicare generally accepts modifier 50 on one line, while some commercial payers require the two-line format. The wrong format causes a technical denial even when the procedure was documented correctly.

Related CPT codes: 36476, 36478, 36479, 36482, and 36483

CPT code 36475 sits in a family of vein ablation codes. They are separated by modality, by the number of veins treated, and by whether the code is primary or add-on. Knowing the family prevents under-billing when several veins are closed in one session.

CPT 36475 vs 36478: Radiofrequency vs laser ablation

CPT 36475 and CPT 36478 are not interchangeable. The modality used during the procedure decides the code. Both cover the first treated vein and both include imaging guidance. The difference is the energy source. CPT 36475 uses a radiofrequency catheter, and CPT 36478 uses a laser fiber at 980, 1320, or 1470 nm.

Medicare rates for the two codes are similar but not identical, so check the current year in the AAPC CPT code lookup. Reporting 36475 when a laser fiber was used misrepresents the service.

Documentation requirements for a paid claim

Documentation is where most 36475 denials start. Payers run post-payment audits on vein ablation claims, and one missing element turns a paid claim into a recoupment demand. The diagnosis specificity in the record also has to match what goes out on the claim.

Each of the following must be in the medical record before the procedure date:

• Duplex ultrasound report: Reflux of at least 0.5 seconds in the target vein on standing, carrying the interpreting physician’s signature and the measurements.
• Conservative therapy log: Compression stocking grade, usually 20-30 mmHg or 30-40 mmHg, plus duration of use and outcome. Most MACs require 6 weeks minimum and some require 3 months. A patient-reported history without clinical corroboration is generally not enough.
• Procedure-specific symptoms: Documented pain, heaviness, swelling, skin changes such as lipodermatosclerosis or stasis dermatitis, or ulceration attributed to venous insufficiency.
• Operative note: The approach, catheter insertion site, treated vein segment, radiofrequency parameters applied, and post-procedure duplex confirmation of closure.
• Physician attestation of medical necessity: A signed statement giving the clinical rationale for ablation over continued conservative management.

The duplex study itself is a separate billable service. A bilateral duplex scan of the extremity veins is reported with CPT 93970, and a unilateral or limited study with CPT 93971. The order of these records matters as much as their contents, because each one has to pre-date the step that relies on it.

Global period, prior authorization, and common billing pitfalls

CPT code 36475 carries a 000 global period on the Medicare physician fee schedule. Bundling therefore applies only to related services performed on the day of the procedure. There is no 10-day postoperative window, so a follow-up visit the following week is billed on its own merits.

A significant, separately identifiable E/M service on the procedure date is reported with modifier 25. Modifier 24 has no role here, because it covers E/M inside a 10-day or 90-day postoperative period.

Prior authorization requirements vary by payer. Traditional Medicare does not require it for this code in most jurisdictions, but commercial payers and Medicare Advantage plans often do. Some payers want authorization for the diagnostic duplex ultrasound as well as the ablation. Verify with each payer before scheduling.

The pitfalls that come up most often on 36475 claims are these:

• Wrong POS code: An OBL billed as POS 22 instead of POS 11, which pays the facility rate on a non-facility service.
• Missing add-on code: Two veins treated, but only 36475 reported instead of 36475 plus 36476.
• Unbundling imaging guidance: Billing a separate ultrasound guidance code when imaging already sits inside the 36475 descriptor.
• Modifier 50 versus RT and LT: Modifier 50 submitted where the commercial payer requires two separate lines.
• Conservative therapy not documented: The claim goes out before the compression stocking trial appears in the record.

How Pabau keeps vein ablation claims clean

Vein ablation billing is rule-dense. POS-specific rates, add-on code pairing, bilateral modifier logic, and MAC-specific documentation thresholds all sit between the procedure room and the remittance. Each one is a place where a correctly performed procedure turns into an incorrect claim.

Practice management software like Pabau connects the clinical record to the claim, so the two cannot drift apart. Pabau’s software for vein practices scrubs each claim before submission and flags three things:

• POS mismatches between the visit record and the claim
• Missing add-on codes when the operative note documents a second vein
• Modifier conflicts that would trip an NCCI edit

Documentation templates can be structured to capture duplex findings, reflux measurements, conservative therapy history, and operative detail. Those fields then map straight onto payer audit criteria, so the chart answers an audit before anyone asks.

For sessions that bill both 36475 and 36476, automated code pairing confirms the add-on never leaves without its primary code. Getting the claim right first time cuts resubmission cycles and shortens the wait for payment.

Streamline your vein ablation billing workflow

Pabau’s claims management software helps vascular and phlebology practices flag POS mismatches, modifier conflicts, and NCCI edits before submission. See how automated claim scrubbing and integrated documentation reduce 36475 denials.

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Conclusion

The money on a 36475 claim is decided long before the catheter goes in. A duplex report dated after the compression trial will cost the claim. So will a POS digit that does not match where the procedure actually happened.

Set the documentation sequence once, inside a template, and the coding follows from it. Practices that do this answer far fewer MAC questions about reflux thresholds. They also rework fewer claims that were clinically correct all along.

Book a demo to see how Pabau scrubs vein ablation claims and keeps the duplex, compression, and operative records in one chart.

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