Aimovig denials in California external review

In the California DMHC record, independent physician reviewers decided 30 published external-review cases involving Aimovigand overturned the plan’s denial in 73.3%. That is a historical result among cases that reached this program, not a forecast for an individual appeal.

California DMHC decisions
30
2018–2025
Overturned
73.3%
22 denials reversed

By condition

Published outcomes when Aimovig was denied for these conditions.
ConditionDecisionsOverturned
Chronic Migraine15
80%
Migraine12
58.3%

What the insurer actually argued

Denials fall into different categories, and they don’t succeed equally — so the reason on your letter changes how you should answer it.
Reason givenDecisionsOverturned
Medical Necessity
The plan said the care wasn’t medically necessary. The most common fight, and the most winnable.
27
77.8%
Experimental/Investigational
The plan called the treatment unproven. These turn on published evidence, so the appeal is a literature argument.
3
33.3%
Typical time to a decision
10 days
Most land between 4 and 16 days
Handled as urgent
46.7%
Expedited when a delay would cause harm

What the reviewers wrote

Excerpts from the independent reviewers’ published findings — the actual reasoning, quoted, not summarised.

Where the denial was overturned

Findings: The physician reviewer found that Nature of Statutory Criteria/Case Summary: The patient has requested authorization and coverage for Aimovig 70 mg monthly injections. Chronic migraine, as defined by the International Classification of Headache Disorders, is diagnosed when a patient experiences 15 or more headaches per month for three or more months, in which eight or more headaches per month meet the criteria for migraine with and without aura or respond to migraine-specific treatment. Four injectable preventive therapies are available, including Botox and three monoclonal antibodies (mAbs) targeting calcitonin gene‐related peptide (CGRP), such as Aimovig.
Medical Necessity · 2024 · IMR MN24-40900
Findings: The physician reviewer found that Nature of Statutory Criteria/Case Summary: The patient has requested authorization and coverage for Aimovig 140 mg/mL injectable medication. Applying the guidelines from the American Headache Society (AHS) and findings from the current medical literature, this patient meets the requirements for treatment with Aimovig. The records document that the patient has a history of chronic intractable migraine without aura and essential tremor. The patient has failed treatment with Topamax and Depakote. The patient has experienced a reprieve from migraines since starting treatment with Aimovig.
Medical Necessity · 2023 · IMR MN23-39470

Where the denial was upheld

Worth reading too — these show what an appeal has to overcome.
Nature of Statutory Criteria/ Case Summary: The enrollee’s parent requested authorization and coverage for the injectable medication, Aimovig, for treatment of chronic migraine headaches.According to the medical record, the enrollee has chronic migraine headaches, status migrainosus, and tectal glioma (a benign lesion in his brain). He underwent endoscopic third ventriculostomy (ETV) surgery for hydrocephalus. He is followed by a neurologist for symptoms of daily headaches with pain spikes. He also gets nausea, lightheadedness, light sensitivity, movement sensitivity, and noise sensitivity associated with the migraines. He has missed a lot of time at school. For his symptoms, he has tried treatment with Propranolol, amitriptyline, Venlafaxine, riboflavin, Melatonin, Sumatriptan, Rizatriptan, Vicodin, Norco, Diclofenac, Compazine, Zofran, Naproxen, and vaping THC.
Experimental/Investigational · 2019 · IMR EI19-30951
Nature of Statutory Criteria/Case Summary: An enrollee has requested authorization and coverage for Aimovig.Aimovig (erenumab) is a calcitonin gene-related peptide (CGRP) approved for episodic and chronic migraine. CGRP monoclonal antibodies (mAbs) are biologic agents that have demonstrated efficacy, safety, and tolerability for the preventive treatment of episodic and chronic migraine in phase 2 and phase 3 randomized, placebo-controlled trials. Erenumab can be administered every four or 12 weeks by subcutaneous injection and does not require dose titration. Erenumab may achieve rapid treatment effects over days to weeks and is effective in patients who have failed prior preventive treatment, as well as in those on concurrent oral preventive treatments.
Medical Necessity · 2021 · IMR MN21-35635

Figures and quotations on this page come from 42,749 published decisions in the California DMHC Independent Medical Review dataset. These are California external-review outcomes. Other state and federal programs have different eligibility rules, processes, and current availability; the rates here do not transfer to those programs or predict an individual result. Excerpts are quoted verbatim from the public record and describe this treatment generally, not any individual case.

Related guide

Put this treatment in the complete diagnosis-and-drug graph, with the migraine-only denominator disclosed separately: migraine, CGRP drug and Botox denial evidence guide.

How to use this in your appeal

These outcomes describe eligible cases completed through California DMHC’s Independent Medical Review program. They do not estimate the chance that an internal appeal, an external review in another jurisdiction, or your individual case will succeed. Use the record to identify evidence patterns involving Aimovig, then check the rights and deadlines that apply to your plan.

SOURCE: CALIFORNIA DMHC INDEPENDENT MEDICAL REVIEW OUTCOMES (CHHS OPEN DATA) · AGGREGATES + DEIDENTIFIED DECISION EXCERPTS/REFERENCE IDS · METHODOLOGY

Not legal or medical advice. Coverage Rights is a self-help tool that helps you prepare your own appeal. For advice about your specific situation, talk to a licensed attorney or your doctor.

Denied Aimovig? Use the California record to prepare.

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