An estimated 984,535 patients in California are not receiving guideline-appropriate preventive migraine care from their primary care provider
How California compares
California's gap rate of 93.2% is consistent with the national pattern of 90.4%. Of the 2,250 primary care physicians in California actively treating Medicare patients with migraine, 2,096 have never written a CGRP prescription. This is not a California-specific failure — it is a national crisis that California is experiencing alongside 47 other states.
What this means for patients
A patient with frequent migraine who sees their primary care physician in California has a 93.2% chance that their doctor has never prescribed a CGRP-targeting therapy. This is not a reflection of physician knowledge or intent — it is the predictable consequence of prior authorization requirements that make CGRP prescribing administratively prohibitive in primary care.
About the data
Based on CMS Medicare Part D prescribing data — the only publicly available provider-level prescribing dataset in the United States. Active prescriber = 20+ triptan claims in the observation period. Medicare patients represent a subset of the total migraine population; the true gap is likely larger. Full methodology →
Getting CGRPs approved in California
Prior authorization burden is the primary structural explanation for this gap. The Headache Vault PA Engine navigates California payer requirements — covering all major commercial insurers and Medicare Advantage plans. Free for all clinicians, no account required.
Run a PA — free →California Medical Society members: this data and tool are free to share with your members. All data on this page is CC BY 4.0.
Citation
Doty A. Migraine Prescribing Gap in California. The Headache Vault; June 2026. Available at: https://headachevault.com/research/prescribing-gap/california/ Licensed CC BY 4.0. Data: CMS Medicare Part D Prescriber Public Use Files, 2022-2023.