An estimated 311,363 patients in Illinois are not receiving guideline-appropriate preventive migraine care from their primary care provider
How Illinois compares
Illinois's gap rate of 91.8% is consistent with the national pattern of 90.4%. Of the 486 primary care physicians in Illinois actively treating Medicare patients with migraine, 446 have never written a CGRP prescription. This is not a Illinois-specific failure — it is a national crisis that Illinois is experiencing alongside 47 other states.
What this means for patients
A patient with frequent migraine who sees their primary care physician in Illinois has a 91.8% 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 Illinois
Prior authorization burden is the primary structural explanation for this gap. The Headache Vault PA Engine navigates Illinois payer requirements — covering all major commercial insurers and Medicare Advantage plans. Free for all clinicians, no account required.
Run a PA — free →Illinois 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 Illinois. The Headache Vault; June 2026. Available at: https://headachevault.com/research/prescribing-gap/illinois/ Licensed CC BY 4.0. Data: CMS Medicare Part D Prescriber Public Use Files, 2022-2023.