The CGRP step-therapy override most migraine patients never use
Insurers make most CGRP patients fail older preventives first. The step-therapy exception process exists to skip that, and almost nobody files it.
The line in the denial letter
"Not medically necessary at this time." That sentence sits near the top of the denial, just above a line asking for documentation of an inadequate response to two or more preventive agents. The drug your neurologist prescribed, the one in the CGRP class, is sitting behind a wall that has nothing to do with whether it would help you.
The denial is not a no. It is a not-yet: not until you have tried something cheaper and brought back proof. Insurers call it step therapy. Patients call it fail first, because that is exactly what it asks you to do. Take an older drug, let it not work or make you sick, and come back with evidence.
Most people read the letter as the end of the conversation. It is the start of one.
Why CGRP drugs draw the 'fail first' rule
CGRP-targeting preventives, the monoclonal antibodies (erenumab, fremanezumab, galcanezumab, eptinezumab) and the oral gepants (rimegepant, atogepant), sit near the top of most formularies. They are among the most expensive migraine preventives a plan covers, which is why nearly every insurer gates them behind older, off-patent drugs.
The gate often ignores the medicine. The American Headache Society's 2024 position statement argued CGRP-targeting therapies should be available as first-line options, without forcing patients through preventives that were never designed for migraine in the first place. The AHS 2024 position statement recommends CGRP-targeting therapies as first-line migraine prevention without requiring prior treatment failure. ([source](https://www.neurologylive.com/view/american-headache-society-cgrp-medications-considered-first-line-migraine-preventive-treatments)) Topiramate, amitriptyline, and propranolol were borrowed from epilepsy, depression, and blood-pressure medicine. Your plan may still want two of them documented before it will say yes to the class built for migraine.
What they make you try first
The exact list varies by plan, but the categories are predictable. Step-therapy protocols on the CGRP class almost always draw from a handful of older preventive families, and most plans want documented trials of at least two before they reconsider. For chronic migraine (15 or more headache days a month), some plans add a Botox trial to the list as well.
Drug class
Common examples
Originally built for
Beta-blockers
Propranolol, metoprolol, timolol
High blood pressure
Antiepileptics
Topiramate, divalproex sodium
Seizures
Tricyclic antidepressants
Amitriptyline, nortriptyline
Depression
ARBs
Candesartan
Blood pressure
Common older preventive classes insurers require before approving a CGRP-targeting drug. Specific requirements vary by plan and formulary.
The exception almost nobody files
Buried in most plan documents, and written into step-therapy reform laws in a majority of states, is an override. As of 2025, 35 states have enacted some type of step therapy reform. ([source](https://aimedalliance.org/wp-content/uploads/2025/06/AA-2025StateReport_June_2025.pdf)) Your prescriber can request a step-therapy exception, and the insurer is generally required to grant it when one of a few specific conditions is true.
The condition most migraine patients meet is the one they never claim. If you tried topiramate three years ago and stopped because of the cognitive fog, that counts as a documented failure, even though it predates this prescription, this neurologist, and sometimes this insurer. You do not have to re-fail a drug you already failed.
The five grounds for a step-therapy exception
Most state laws and plan documents require an exception when one of these is true: (1) the required drug is contraindicated or likely to cause harm; (2) you already tried it and it failed, on this plan or a previous one; (3) it is expected to be ineffective given your history; (4) you are already stable on the CGRP drug; (5) the required drug is not in your medical best interest. Number 2 is the one most patients qualify for and never claim.
What actually moves the appeal
The exception form has a field your prescriber fills in, and a field where evidence goes. Evidence is where most appeals run thin. "Patient failed topiramate" is weaker than "patient trialed topiramate 100mg for 9 weeks; attack frequency unchanged at 12 days per month; discontinued for cognitive slowing." Dates, doses, duration, the side effect that ended it, the attack count that never moved.
This is the part the clinic chart usually cannot supply, because the chart only holds the appointments. The drug failed in the weeks between visits, not in the room. A continuous record of what those weeks looked like, attack days plus the residual postdrome fog and the days you lost after the headache lifted, is the difference between a one-line note and an appeal the reviewer cannot wave off.
That continuous record is what we built Postdrome to hold: the trial-and-failure timeline an appeal actually runs on. Which preventive you were on, when, and how many days you lost to attacks and to the postdrome after, kept on your device and exported as your own data.
The drug failed in the weeks between visits, not in the room.
When to push, and where to get help
If the exception is denied, you are not finished. Most plans owe you an internal appeal and then an external review by an independent physician, and a denial of a guideline-supported therapy has a real track record of turning over at that stage. Your state insurance commissioner takes complaints. The American Migraine Foundation publishes appeal-letter templates you can hand your prescriber.
One thing not to do while you wait: stop documenting. The trial you are on right now, including the postdrome days the headache log misses, is the next exhibit if the appeal goes another round.
The override exists. The plans count on you not knowing it does.
Build the symptom record an appeal can't wave off.
Postdrome keeps a continuous symptom timeline, attack days plus the postdrome hours after, on your device and exportable as your own file. It is the record a step-therapy appeal runs on, and the one a clinic chart cannot produce on its own.
