Nipocalimab-aahu (Imaavy) — CPB 1083 | AETNA Coverage Update

Aetna modified CPB 1083 to add coverage criteria for nipocalimab-aahu (Imaavy) for generalized myasthenia gravis, effective January 5, 2026. Here's what billing teams need to do.

Aetna, a CVS Health company, published this new Imaavy coverage policy under CPB 1083 in the Aetna system, establishing the first formal medical necessity criteria for this recently FDA-approved FcRn blocker. The primary billing code for the drug itself is HCPCS C9305 (injection, nipocalimab-aahu, 3 mg). The policy covers commercial medical plans only — Medicare Part B has a separate pathway. If your practice treats generalized myasthenia gravis (gMG) and bills Aetna, this coverage policy applies to you starting now.

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Quick-Reference Table

Field	Detail Copy
Payer	Aetna, a CVS Health company
Policy	Nipocalimab-aahu (Imaavy) — CPB 1083
Policy Code	CPB 1083
Change Type	Modified (new drug criteria added)
Effective Date	January 5, 2026
Impact Level	High — new specialty drug requiring precertification
Specialties Affected	Neurology, neuromuscular medicine, infusion centers, specialty pharmacy
Key Action	Set up precertification workflows for HCPCS C9305 before billing any Imaavy claims

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Aetna Nipocalimab-aahu (Imaavy) Coverage Criteria and Medical Necessity Requirements 2026

The Aetna nipocalimab-aahu coverage policy sets a narrow bar for initial approval. Every single criterion below must be met — this is not a checklist where four out of five is good enough.

Antibody status: The member must be anti-AChR or anti-MuSK antibody positive. CPT codes 86041 (AChR binding antibody), 86042 (blocking antibody), 86043 (modulating antibody), and 86366 (MuSK antibody) are the lab codes tied to this requirement. If you're billing for Imaavy, make sure those antibody results are documented in the chart and referenced in your prior authorization submission.

Disease severity: The member must have an MGFA clinical classification of II through IV and an MG-ADL total score of five or higher. That score threshold is specific — a four won't clear this. Document both the MGFA classification and the MG-ADL score explicitly in the precertification request.

Prior treatment failure: This is where most prior authorization denials will happen. The member must meet one of three paths:

#	Covered Indication Copy
1	Failed at least two immunosuppressive therapies over 12 months (azathioprine, corticosteroids, cyclosporine, methotrexate, mycophenolate, or tacrolimus)
2	Failed at least one immunosuppressive therapy and IVIG over 12 months
3	Has a documented clinical reason to avoid both immunosuppressives and IVIG

The 12-month duration requirement is real and will be scrutinized. A six-month trial of azathioprine plus a recent IVIG failure won't satisfy it unless the cumulative timeline reaches 12 months. Build that timeline into your documentation before you submit.

Prior authorization is required for all Aetna participating providers and members in applicable plan designs. Call (866) 752-7021 or fax the Statement of Medical Necessity form to (888) 267-3277. Aetna's site of care utilization management policy also applies — infusion site matters for reimbursement here, so verify where the infusion will be delivered before you precert.

All other indications for nipocalimab-aahu are considered experimental, investigational, or unproven by Aetna. gMG is the only covered use under this policy.

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Aetna Imaavy Exclusions and Non-Covered Indications

The combination exclusion in CPB 1083 is worth calling out separately. Aetna will not cover Imaavy when used alongside:

#	Excluded Procedure Copy
1	Another neonatal Fc receptor (FcRn) blocker — specifically Rystiggo (rozanolixizumab-noli, J9333) or Vyvgart/Vyvgart Hytrulo (efgartigimod alfa, J9332 and J9334)
2	A complement inhibitor — specifically Soliris (eculizumab, J1299/J1300), Ultomiris (ravulizumab-cwvz, J1303), or Zilbrysq

This is a hard exclusion, not a clinical judgment call. If a member is currently on efgartigimod or rozanolixizumab and the provider wants to switch to nipocalimab-aahu, the existing therapy must be discontinued first. The policy doesn't define a washout period, so document the discontinuation clearly.

If you see a claim come through with C9305 billed alongside J9332, J9333, or J9334, expect a claim denial. Build an edit into your charge capture to flag that combination.

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Coverage Indications at a Glance

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Aetna Nipocalimab-aahu Billing Guidelines and Action Items 2026

These are the steps your billing team needs to take now. The effective date of January 5, 2026 is already past — if you haven't set these up yet, you're behind.

Copy Action Items

If you're unsure how this policy applies to your specific payer contract or member population, talk to your compliance officer before submitting your first Imaavy claim. The combination exclusion and site-of-care requirements add compliance complexity that's worth a direct review.

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CPT, HCPCS, and ICD-10 Codes for Nipocalimab-aahu Under CPB 1083

Covered HCPCS Code (When Selection Criteria Are Met)

Code	Type	Description Copy
C9305	HCPCS	Injection, nipocalimab-aahu, 3 mg

Antibody Testing CPT Codes

Infusion Administration CPT Codes

IVIG / Immune Globulin CPT Codes

Code	Type	Description Copy
90283	CPT	Immune globulin (IgIV), human, for intravenous use
90284	CPT	Immune globulin (SCIg), human, for use in subcutaneous infusions, 100 mg

Excluded Combination Therapy HCPCS Codes (FcRn Blockers and Complement Inhibitors)

Immunosuppressive Therapy HCPCS Codes (Prior Treatment Failure Documentation)

Corticosteroid HCPCS Codes

IVIG HCPCS Codes (Prior Treatment Failure Documentation)

Key ICD-10-CM Diagnosis Codes

Code	Description Copy
G70.0	Myasthenia gravis without (acute) exacerbation
G70.1	Myasthenia gravis with (acute) exacerbation

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