Nusinersen (Spinraza) — CPB 0915 | AETNA Coverage Update

Aetna modified CPB 0915 for nusinersen (Spinraza) coverage, effective December 10, 2025. Here's what billing teams need to know before submitting claims.

Aetna, a CVS Health company, updated its Spinraza nusinersen coverage policy under CPB 0915 Aetna system, adding detailed criteria for members who previously received gene replacement therapy like Zolgensma and now seek Spinraza coverage. The policy affects claims billed under HCPCS J2326 (injection, nusinersen, 0.1 mg) and a range of intrathecal administration codes including CPT 62323 and 96450. If your practice treats SMA patients on commercial Aetna plans, this update directly changes how you document and bill continuation therapy in 2025 and beyond.

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Quick-Reference Table

Field	Detail Copy
Payer	Aetna, a CVS Health company
Policy	Nusinersen (Spinraza) – CPB 0915
Policy Code	CPB 0915
Change Type	Modified
Effective Date	December 10, 2025
Impact Level	High
Specialties Affected	Neurology, Pediatric Neurology, Neuromuscular Medicine, SMA specialty centers
Key Action	Update prior authorization workflows and baseline assessment documentation before billing J2326 for any member with prior gene therapy history

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Aetna Nusinersen (Spinraza) Coverage Criteria and Medical Necessity Requirements 2025

Aetna's Spinraza nusinersen coverage policy requires precertification for all participating providers and members on applicable commercial plans. Call (866) 752-7021 or fax (888) 267-3277 to initiate prior authorization. Don't wait until the claim is ready — start the precertification process before the first dose.

The medical necessity criteria for initial approval are tighter than many billing teams expect. All seven of the following conditions must be met — not a subset, all of them.

1. SMA Type
The member must have type 1, type 2, or type 3 SMA. Type 4 is not listed as a covered indication.

2. Genetic Documentation
Aetna requires genetic documentation of 5q SMA homozygous gene mutation, homozygous gene deletion, or compound heterozygote. Submit this with the prior authorization request. Missing genetic documentation is a fast path to claim denial.

3. Ventilation Status
Members dependent on invasive ventilation, tracheostomy (ICD-10 Z93.0), or non-invasive ventilation beyond naps and nighttime sleep do not qualify. Flag Z99.11 (ventilator dependence status) in your records review before initiating prior auth.

4. Baseline Assessment Documentation
Aetna requires chart notes or lab values showing a baseline assessment using at least one of these tools, matched to the member's age and motor ability:

#	Covered Indication Copy
1	Hammersmith Infant Neurological Exam Part 2 (HINE-2)
2	Hammersmith Functional Motor Scale Expanded (HFMSE)
3	Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND)

No baseline documentation means no approval. Build this into your intake workflow now.

5. Prior Gene Therapy History — The Critical New Wrinkle
This is the most significant change in the updated policy. Members who have never received gene replacement therapy for SMA (e.g., Zolgensma) qualify under the standard path. Members who have received prior gene therapy face a higher bar — they must show a documented clinical decline since receiving that therapy. Specifically, they must show a decline meeting the minimally clinical important difference on one of the three assessment tools:

#	Covered Indication Copy
1	HINE-2: Decline of at least 2 points on kicking AND 1 point on any other milestone (excluding voluntary grasp)
2	HFMSE: Decline of at least 3 points
3	CHOP-INTEND: Decline of at least 4 points

ICD-10 code Z94.84 (stem cells transplant status — gene therapy) will flag these members in your system. If you see Z94.84 on a claim, your documentation must include scored assessments showing decline. Without it, the prior authorization will fail.

6. No Concurrent Risdiplam (Evrysdi) Use
Members cannot use Spinraza and Evrysdi at the same time. Document this explicitly in your clinical notes.

7. Loading Dose Protocol
If the member has not received a loading dose, the regimen is 12 mg (5 mL) on Day 0, 14, 28, and 58. This aligns with how you'd bill J2326 — remember, J2326 is billed per 0.1 mg, so a 12 mg dose = 120 units per administration.

Site of Care Matters
Aetna has designated Spinraza as a GCIT (Gene-based, Cellular & Other Innovative Therapies) product. Unless the member's plan has opted out, Spinraza must be administered at an Aetna Institutes® GCIT Network site. Verify network status before scheduling — an out-of-network administration creates a reimbursement problem that no amount of documentation fixes afterward.

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Aetna Nusinersen (Spinraza) Exclusions and Non-Covered Indications

The policy does not cover Spinraza for members with type 4 SMA or SMA without the 5q genetic documentation. Ventilator-dependent members (Z99.11) and those with tracheostomy (Z93.0) are explicitly excluded from initial approval criteria.

Members who previously received gene replacement therapy and have not experienced documented clinical decline since that therapy are not eligible. Prior gene therapy alone (Z94.84) doesn't disqualify a member — but it triggers the decline documentation requirement. If you can't show the scored assessment decline, the claim won't pass medical necessity review.

Concurrent use with risdiplam (Evrysdi) is not covered. If a member is active on Evrysdi, Spinraza prior authorization will be denied until Evrysdi is discontinued.

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Coverage Indications at a Glance

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Aetna Nusinersen (Spinraza) Billing Guidelines and Action Items 2025

1. Audit your active Spinraza patients for Z94.84 before December 10, 2025.
Any member with prior gene therapy history needs a scored functional assessment on file. If you don't have HINE-2, HFMSE, or CHOP-INTEND scores showing decline to the MCID threshold, you cannot support the prior authorization. Identify these patients now and coordinate with your clinical team to document.

2. Verify GCIT network status for every administration site.
Spinraza administered outside an Aetna Institutes® GCIT Network site will not meet the coverage policy requirements — unless the member's specific plan has opted out of that requirement. Confirm site designation before the effective date of December 10, 2025. Call Aetna's GCIT line or check the designated networks page directly.

3. Bill J2326 at the correct unit count.
HCPCS J2326 is billed per 0.1 mg. A standard 12 mg dose requires 120 units. A common billing error is submitting 1 unit for the full vial. That generates a reimbursement discrepancy and triggers review. Update your charge capture template now.

4. Match assessment tool to member age and motor ability in your documentation.
Aetna specifies that the assessment tool must be appropriate for the member's age and motor ability. Don't submit HFMSE scores for an infant who should be assessed on CHOP-INTEND. Mismatched tools cause prior authorization delays even when the clinical data is solid.

5. Confirm prescriber specialty documentation is in the chart.
The policy requires that Spinraza be prescribed by or in consultation with a physician who specializes in SMA treatment. If your prescribing physician isn't the SMA specialist, get the consulting physician's documentation into the chart before submitting the prior auth. This is a hard requirement, not a soft preference.

6. For members restarting after gene therapy: re-run the full initial criteria workflow.
The policy is explicit here. Members who were on Spinraza, received Zolgensma, and now want to restart Spinraza must meet all initial criteria — not continuation criteria. Your prior auth workflow for these patients must mirror a new-start submission, not a renewal. If your system auto-routes prior gene therapy patients to a continuation workflow, fix that routing before December 10, 2025.

7. Document concurrent therapy status for every submission.
Aetna requires attestation that the member will not use Spinraza and Evrysdi at the same time. Build a concurrent therapy check into your prior authorization intake form. A missing attestation can delay or deny approval.

If you're unsure how this policy applies to a specific patient mix or plan design, talk to your compliance officer before the effective date. The interaction between prior gene therapy, GCIT site requirements, and the new decline thresholds creates enough complexity that a compliance review is worth the time.

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CPT, HCPCS, and ICD-10 Codes for Nusinersen (Spinraza) Under CPB 0915

HCPCS Codes — Primary Billing Codes

Code	Type	Description Copy
J2326	HCPCS	Injection, nusinersen, 0.1 mg
A4221	HCPCS	Supplies for maintenance of drug infusion catheter, per week (list drug separately)
A4301	HCPCS	Implantable access total catheter, port/reservoir (e.g., venous, arterial, epidural, subarachnoid)

CPT Codes — Administration, Guidance, and Monitoring

CPT Codes — Biomarker Monitoring

Code	Type	Description Copy
0361U	CPT	Neurofilament light chain, digital immunoassay, plasma, quantitative
0547U	CPT	Neurofilament light chain (NfL), chemiluminescent enzyme immunoassay, plasma, quantitative
86316	CPT	Immunoassay for tumor antigen, other antigen, quantitative (S100B)

Key ICD-10-CM Diagnosis Codes

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