Palivizumab (Synagis) — CPB 0318 | AETNA Coverage Update

Aetna modified CPB 0318 for palivizumab (Synagis), effective November 26, 2025. Here's what changes for billing teams.

Aetna, a CVS Health company, updated its Palivizumab (Synagis) coverage policy under CPB 0318. The most significant addition: any member who received nirsevimab-alip (Beyfortus) in the same RSV season is now explicitly excluded from Synagis coverage. The primary billing code affected is CPT 90378. If your practice or pharmacy bills Synagis to Aetna commercial plans, this exclusion changes how you screen patients before each RSV season.

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Quick-Reference Table

Field	Detail Copy
Payer	Aetna, a CVS Health company
Policy	Palivizumab (Synagis) — CPB 0318
Policy Code	CPB 0318
Change Type	Modified
Effective Date	November 26, 2025
Impact Level	High — active RSV season overlap risk
Specialties Affected	Pediatrics, neonatology, pediatric cardiology, pediatric pulmonology, infectious disease, specialty pharmacy
Key Action	Screen all Synagis candidates for prior Beyfortus administration before submitting precertification for CPT 90378

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Aetna Palivizumab Coverage Criteria and Medical Necessity Requirements 2025

Aetna's coverage policy for palivizumab under CPB 0318 covers up to five doses per RSV season under CPT 90378. Those doses are for the prevention of serious lower respiratory tract disease caused by RSV. Medical necessity applies only when a member meets one of seven specific diagnoses — and each diagnosis carries its own sub-criteria. Meeting the diagnosis alone is not enough.

Precertification is required for all Aetna participating providers and members in applicable plan designs. Call (866) 752-7021 or fax (888) 267-3277. Get your Statement of Medical Necessity (SMN) form from the Specialty Pharmacy Precertification page on Aetna's provider portal before submitting.

Here's how Aetna defines medical necessity by diagnosis category:

Prematurity: Both criteria must be met — gestational age under 29 weeks, 0 days, and chronological age under 12 months at the start of RSV season.

Chronic Lung Disease (CLD) of Prematurity: All three criteria must be met — gestational age under 32 weeks, 0 days; need for greater than 21% oxygen for at least the first 28 days after birth; and age under 12 months at first RSV season start, or age under 24 months at a subsequent RSV season if the member still requires medical support (chronic corticosteroids, diuretic therapy, or supplemental oxygen) in the prior six months.

Congenital Heart Disease (CHD): The CHD must be hemodynamically significant. The member must be under 12 months at RSV season start, or between 12 and 24 months and scheduled for cardiac transplantation during the RSV season.

Congenital Airway Abnormality: The condition must compromise handling of respiratory secretions, and the member must be under 12 months at RSV season start.

Neuromuscular Condition: Same criteria as congenital airway abnormality — secretion compromise plus age under 12 months at RSV season start.

Immunocompromised Children: The member must be profoundly immunocompromised during RSV season — think SCID, stem cell transplant, or bone marrow transplant — and under 24 months at RSV season start.

Cystic Fibrosis: Either under 12 months with evidence of CLD or nutritional compromise, or between 12 and 24 months with manifestations of lung disease such as hospitalizations.

Each of these pathways has hard age cutoffs. Document the member's gestational age, chronological age, and clinical support requirements in your prior authorization submission. Missing one data point is enough for Aetna to deny.

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Aetna Palivizumab Exclusions and Non-Covered Indications

The new exclusion in the November 26, 2025 update is the one that will generate claim denial if your team misses it: Aetna will not cover palivizumab (Synagis) for any member who has already received nirsevimab-alip (Beyfortus) in the same RSV season.

This is the real issue here. Beyfortus and Synagis target RSV through different mechanisms, but Aetna treats them as mutually exclusive within a single season. If a patient received Beyfortus through a pediatrician or birth hospital — which is increasingly common since Beyfortus became widely available — Synagis is off the table for that season.

The problem billing teams will face: Beyfortus administration often happens at a different facility. You may not know a patient received it unless you ask. Add a Beyfortus screening question to your intake process now, before the next RSV season. A Synagis prior authorization submitted without that check is a denial waiting to happen.

Aetna points to CPB 1038 for the full nirsevimab-alip (Beyfortus) policy. Cross-reference that bulletin if you need to understand what Aetna covers on the Beyfortus side.

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Coverage Indications at a Glance

All covered indications require precertification for CPT 90378. Reimbursement depends on precertification approval — do not administer before authorization is confirmed.

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Aetna Palivizumab Billing Guidelines and Action Items 2025

The effective date of November 26, 2025 lands mid-RSV season. That timing matters. Members may already be partway through a Synagis course — or may have received Beyfortus earlier in the season without your team's knowledge. Act on these items now.

Copy Action Items

If you have members in overlapping situations — for example, a patient who received one dose of Beyfortus but whose clinical team believes Synagis is still indicated — loop in your compliance officer before submitting. The exclusion language in CPB 0318 is categorical for the same RSV season, but edge cases exist. Don't guess on high-cost specialty pharmacy claims.

Synagis is a high-cost specialty medication. A denied multi-dose course represents significant revenue exposure. The documentation requirements here are not a formality.

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CPT, HCPCS, and ICD-10 Codes for Palivizumab Under CPB 0318

Covered CPT Codes (When Selection Criteria Are Met)

Code	Type	Description Copy
90378	CPT	Respiratory syncytial virus, monoclonal antibody recombinant, for intramuscular use, 50 mg each

Other CPT Codes Referenced in CPB 0318

These codes appear in the bulletin as clinically related procedures — primarily cardiac surgeries relevant to the congenital heart disease indication. They are not separately billed for Synagis administration, but document the clinical context Aetna expects for CHD-based approvals.

Note: The policy data indicates 10 additional CPT codes beyond those listed above. Review the full CPB 0318 policy at the Aetna provider portal for the complete list.

Key ICD-10-CM Diagnosis Codes

The policy data references 166 ICD-10-CM codes across 80+ categories. The full code set is available in CPB 0318 on the Aetna provider portal. The diagnosis codes map to the seven indication pathways described above — prematurity, CLD of prematurity, CHD, congenital airway abnormality, neuromuscular conditions, immunocompromised status, and cystic fibrosis. Ensure your ICD-10 codes match the specific indication pathway used for the precertification.

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