Varicose Veins Treatment and Other Vein Embolization Procedures | UHC Coverage Update

TL;DR: UnitedHealthcare modified its Medicare Advantage coverage policy for varicose vein treatment and vein embolization procedures, effective September 26, 2025. Here's what changes for billing teams.

UnitedHealthcare updated the varicose-veins-treatment-other-vein-embolization-procedures policy to clarify coverage rules for two specific procedure categories: stab phlebectomy with fewer than 10 incisions, and endomechanical ablation of incompetent extremity veins (ClariVein®/MOCA). The primary CPT codes affected are 36473, 36474, and 37799. If your practice bills for vein ablation or phlebectomy under Medicare Advantage, this coverage policy change affects how you route coverage determination—and which criteria source controls your claim.

Quick-Reference Table

UnitedHealthcare Varicose Vein Treatment Coverage Criteria and Medical Necessity Requirements 2025

The core structure of this updated coverage policy comes down to a two-track system. If your state has an active Local Coverage Determination (LCD) or Local Coverage Article (LCA) for the procedure in question, that LCD/LCA controls. If your state doesn't have one, a fallback criteria source applies — and the fallback is different depending on which procedure you're billing.

That distinction matters more than most billing teams realize.

Stab Phlebectomy with Fewer Than 10 Incisions (CPT 37799)

Medicare has no National Coverage Determination (NCD) for stab phlebectomy with fewer than 10 incisions. Coverage is governed entirely at the local level, through LCDs and LCAs set by Medicare Administrative Contractors (MACs).

Where an LCD or LCA exists, compliance with that policy is required. Where no LCD or LCA exists, UnitedHealthcare directs you to InterQual® CP: Procedures, Phlebectomy, Lower Extremity Superficial Tributary Varicose Vein as the criteria source for medical necessity determinations.

CPT 37799 — unlisted vascular surgery procedure — is the billing vehicle for stab phlebectomy fewer than 10 incisions in this context. Because it's an unlisted code, documentation requirements are heightened. You need to establish medical necessity clearly, and you need to know which criteria set applies in your state before you submit.

Endomechanical Ablation of Incompetent Extremity Veins (CPT 36473, 36474)

This is where the policy gets more nuanced. Endomechanical ablation goes by several names — ClariVein®, mechanochemical ablation (MOCA), mechanico-chemical endovenous ablation (MCEA), and mechanically enhanced endovenous chemical ablation (MEECA). All of these refer to the same category of procedure for billing purposes.

Like stab phlebectomy, there's no NCD for this procedure. The same two-track system applies: LCD/LCA where one exists, and a fallback when it doesn't. But here's where UnitedHealthcare's updated coverage policy diverges from the phlebectomy pathway.

For endomechanical ablation in states without an LCD or LCA, the fallback criteria source is the UnitedHealthcare Commercial Medical Policy titled "Surgical and Ablative Procedures for Venous Insufficiency and Varicose Veins" — not InterQual®.

That's a meaningful difference. For stab phlebectomy, the non-LCD fallback is InterQual®. For endomechanical ablation, the non-LCD fallback is a UHC Commercial policy. These are different documents with potentially different medical necessity standards. If your billing team assumes both procedures use the same criteria when no LCD applies, you're setting up for claim denials.

CPT 36473 and CPT 36474 cover endovenous ablation therapy of an incompetent vein in an extremity, inclusive of all imaging guidance. These codes apply to endomechanical ablation when billed under this policy.

Coverage Indications at a Glance

UnitedHealthcare Varicose Vein Billing Guidelines and Action Items 2025

The September 26, 2025 effective date has passed. If you haven't already acted on this policy, act now.

CPT, HCPCS, and ICD-10 Codes for Varicose Vein Treatment Under varicose-veins-treatment-other-vein-embolization-procedures

Covered CPT Codes (When Selection Criteria Are Met)

Note: No HCPCS or ICD-10 codes are listed in this policy update. The policy does not specify ICD-10 diagnosis codes — coverage determination follows the applicable LCD, LCA, or fallback criteria document, which may include their own diagnosis code requirements.

A word on CPT 37799: this unlisted code carries inherent claim denial risk. Payers review unlisted codes manually, and the reimbursement process takes longer. Pair every 37799 claim with an operative report that explicitly addresses the applicable criteria. Gaps in documentation here are where denials happen.