Atidarsagene Autotemcel (Lenmeldy) — CPB 1058 | AETNA Coverage Update

Aetna modified CPB 1058 for atidarsagene autotemcel (Lenmeldy), effective September 26, 2025. Here's what billing teams need to know before submitting claims.

Aetna, a CVS Health company, updated its Lenmeldy coverage policy under CPB 1058 Aetna system. This policy governs a one-time gene therapy for metachromatic leukodystrophy (MLD), billed under HCPCS J3391. The update affects precertification requirements, site-of-care mandates, and the full code set—including CPT 38204, 38206, 81405, and a large block of EMG and nerve conduction codes. If your facility treats pediatric patients with MLD or performs stem cell harvesting in support of gene therapy, this change touches your revenue cycle directly.

Quick-Reference Table

Aetna Lenmeldy Coverage Criteria and Medical Necessity Requirements 2025

The primary covered indication under this coverage policy is metachromatic leukodystrophy, ICD-10-CM E75.25. This is a rare, inherited lysosomal storage disorder caused by arylsulfatase A (ARSA) deficiency. Lenmeldy is a one-time, autologous hematopoietic stem cell gene therapy—meaning the patient's own cells are harvested, genetically modified, and reinfused.

Medical necessity criteria under CPB 1058 center on E75.25 as the confirmed diagnosis. The policy also references neoplasms (C00.0–D49.9) in the ICD-10 code set, which reflects the conditioning regimens and hematopoietic progenitor cell work that overlap with oncology billing. That overlap matters for your billing team when coding the preparatory steps alongside J3391.

Aetna requires precertification for all Lenmeldy administrations. This is not optional and applies to all participating providers and members in applicable plan designs. Contact National Medical Excellence (NME) directly at 877-212-8811 to initiate precertification. Do not assume standard prior authorization channels cover this—NME is the specific contact point.

The real issue here is site-of-care. Unless a member's plan has explicitly opted out of the requirement, Lenmeldy must be administered at an Aetna Institutes® Gene Based, Cellular and Other Innovative Therapy (GCIT®) Network facility. This is a hard stop. Administering outside a designated GCIT site without plan-level opt-out documentation will almost certainly result in claim denial. Verify GCIT designation for your facility before scheduling any infusion.

Coverage Indications at a Glance

Aetna Lenmeldy Billing Guidelines and Action Items 2025

This is a high-stakes therapy. Lenmeldy carries a list price in the millions. A single precertification miss or site-of-care error doesn't just delay a claim—it can create a financial exposure your practice or facility can't absorb. Follow these steps before the September 26, 2025 effective date governs any new submissions.

CPT, HCPCS, and ICD-10 Codes for Atidarsagene Autotemcel Under CPB 1058

HCPCS Code Covered When Selection Criteria Are Met

Supporting CPT Codes Related to CPB 1058

These codes are not the therapy itself, but they are part of the clinical workflow and billing picture for Lenmeldy. Include them in your charge capture review.

Key ICD-10-CM Diagnosis Codes

A Note on the EMG Code Block

The sheer volume of EMG codes (95860–95887) in this policy reflects MLD's neurological nature. These codes document peripheral nervous system involvement—a core part of both diagnosis and treatment monitoring for MLD patients.

Your neurophysiology team needs to understand that these studies aren't incidental. They are part of the clinical justification chain for J3391 approval and ongoing medical necessity. Bill them on the right dates of service, tie them to E75.25, and keep the reports in the chart. Payers pull these records on high-cost gene therapy claims.