Asfotase alfa (Strensiq) — CPB 0901 | AETNA Coverage Update

TL;DR: Aetna, a CVS Health company, modified CPB 0901 for asfotase alfa (Strensiq) effective January 15, 2026. Here's what billing teams need to do before claims start moving through this updated coverage policy.

Aetna's update to CPB 0901 tightens the documentation and monitoring requirements for asfotase alfa (Strensiq) billing across commercial plans. The policy covers subcutaneous injection administration under CPT 96372, with supporting workup codes including CPT 84075 (alkaline phosphatase), CPT 84207 (pyridoxal phosphate), and renal ultrasound codes 76770–76775. If your practice treats pediatric patients with hypophosphatasia (HPP) and bills Aetna commercial, this update directly affects your prior authorization workflow and your continuation-of-therapy documentation.

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Quick-Reference Table

Field	Detail Copy
Payer	Aetna, a CVS Health company
Policy	Asfotase Alfa (Strensiq) — CPB 0901
Policy Code	CPB 0901
Change Type	Modified
Effective Date	January 15, 2026
Impact Level	High
Specialties Affected	Endocrinology, Medical Genetics, Metabolic Bone Disease, Pediatrics, Ophthalmology, Nephrology
Key Action	Confirm baseline ophthalmology and renal ultrasound documentation exists in the chart before submitting precertification on or after January 15, 2026

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Aetna Asfotase Alfa Coverage Criteria and Medical Necessity Requirements 2026

CPB 0901 is Aetna's clinical policy bulletin governing asfotase alfa (Strensiq) for commercial medical plan members. This is a high-cost specialty drug — denials on claims like this carry serious financial exposure per patient annually.

Aetna's Strensiq coverage policy limits approval to two specific HPP onset types: perinatal/infantile onset and juvenile onset. Adult-onset HPP is not covered. That line alone disqualifies a significant portion of potential candidates, and if your treating physician isn't documenting onset timing clearly, you're setting up for a claim denial.

Medical necessity under CPB 0901 requires ALL of the following for initial approval:

Baseline ophthalmology examination (CPT 92012, 92013, or 92014) AND baseline renal ultrasound (CPT 76770–76775) completed before treatment starts

Weekly dose within Aetna's caps — 9 mg/kg/week for perinatal/infantile onset, 6 mg/kg/week for juvenile onset

The baseline ophthalmology and renal ultrasound requirement is the one most likely to trip up billing teams. These aren't optional. Aetna requires both before they'll approve initial therapy. If your center starts Strensiq before completing these workups, you're billing CPT 96372 without the documentation to support prior authorization — and that's a straight denial.

Prior authorization is mandatory. Precertification is required for all Aetna participating providers and members in applicable plan designs. Call (866) 752-7021 or fax (888) 267-3277. You can also use Aetna's Specialty Pharmacy Precertification forms for SMN submissions. Don't start treatment without an auth number in hand.

This medication must be prescribed by — or in documented consultation with — an endocrinologist, geneticist, or a physician specializing in metabolic bone disorders. If a general pediatrician or a hospitalist is the prescribing physician on the claim, expect pushback. Get the specialist documented as the prescriber or the consulting physician before the auth request goes in.

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Aetna Asfotase Alfa Exclusions and Non-Covered Indications

Aetna's Strensiq coverage policy is narrow by design. The policy states explicitly that all indications other than perinatal/infantile-onset and juvenile-onset HPP are considered experimental, investigational, or unproven. Aetna does not enumerate specific excluded conditions by name.

That means adult-onset HPP is not covered under this policy. Any off-label use of asfotase alfa outside perinatal/infantile-onset or juvenile-onset HPP is not covered.

If you're billing CPT 96372 for Strensiq in an adult patient, or in a patient without documented pre-18 onset, Aetna will deny on medical necessity grounds. The ICD-10 codes E83.31 and E83.39 support HPP billing — but the diagnosis code alone won't save a claim if the documentation doesn't support the onset age and disease severity criteria in CPB 0901.

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Coverage Indications at a Glance

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Aetna Asfotase Alfa Billing Guidelines and Action Items 2026

Here's what your billing and clinical documentation teams need to do before and after January 15, 2026.

Copy Action Items

If you're managing a large pediatric HPP panel or aren't sure how the updated criteria map to your patient mix, talk to your compliance officer before the January 15 effective date. The dose cap rules and mandatory monitoring requirements are the two areas most likely to generate denials in year one of this policy revision.

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CPT, HCPCS, and ICD-10 Codes for Asfotase Alfa (Strensiq) Under CPB 0901

Covered CPT Codes (When Selection Criteria Are Met)

A note on CPT 76770–76775: The source policy lists all six retroperitoneal ultrasound codes with identical descriptions. This table reproduces the source list as written. Verify current AMA CPT validity for each code before billing, and confirm with Aetna whether all six apply to your specific claim context or reflect plan-specific billing guidance.

Key ICD-10-CM Diagnosis Codes

A note on the Q85.x codes: The source policy data includes Q85.x neurofibromatosis codes without explanation of their relationship to the HPP indication. Do not use Q85.x codes as the primary diagnosis for asfotase alfa claims. Contact Aetna for clarification on the role of these codes within the full CPB 0901 document.

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