Inclusion Criteria:

• Between the ages of 18 and 75 years.
• Been previously diagnosed with migraine (with or without aura), in accordance with the ICHD-3 criteria.
• Experiences between 8 to 20 headaches days per month (during the last 3 months), with at least 2 of them being migraine days during which the migraines lasted more than 4 hours.
• Onset of migraine at age 50 years or younger.
• Agrees to refrain from initiating or changing the type, dosage, or frequency of any prophylactic medications for indications other than migraine that, in the opinion of the clinician may interfere with the study objectives (e.g., antidepressants, anticonvulsants, beta-adrenergic blockers, etc.).
• Agrees to use nVNS as intended, follow all of the requirements of the study including Follow-up Visit requirements, and record required study data in the subject e-diary.
• Able to provide written informed consent.

Exclusion Criteria:

• Concomitant medical condition that will require oral or injectable steroids during the study.
• Currently on a stable regime of more than 1 migraine preventative therapy.
• History of intracranial aneurysm, intracranial hemorrhage, brain tumor, or significant head trauma.
• Structural abnormality at the nVNS treatment site (e.g., lymphadenopathy, previous surgery, abnormal anatomy).
• Pain at the nVNS treatment site (e.g., dysesthesia, neuralgia, cervicalgia).
• Other significant pain problem (e.g., cancer pain, fibromyalgia, other head or facial pain disorder) that, in the opinion of the Investigator, may confound the study assessments.
• Known or suspected severe cardiac disease (e.g., symptomatic coronary artery disease, prior myocardial infarction, congestive heart failure).
• Known or suspected cerebrovascular disease (e.g., prior stroke or transient ischemic attack, symptomatic carotid artery disease, prior carotid endarterectomy or other vascular neck surgery) or an abnormal baseline electrocardiogram (ECG) within the last year (e.g., second or third-degree heart block, prolonged QT interval, atrial fibrillation, atrial flutter, history of ventricular tachycardia or ventricular fibrillation, clinically significant premature ventricular contraction).
• Previous cervical vagotomy.
• Uncontrolled high blood pressure (systolic >160 mm HG, diastolic >100 mm Hg) after 3 measurements within 24 hours.
• Currently implanted with an electrical and/or neurostimulator device (e.g., cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, cochlear implant, sphenopalatine ganglion stimulator, occipital nerve stimulator).
• Been implanted with metal cervical spine hardware or has a metallic implant near the nVNS stimulation site.
• Known history or suspicion of secondary headache.
• History of syncope (within the last 2 years).
• History of seizure (within the last 2 years).
• Known history or suspicion of substance abuse or addiction (within the last 5 years).
• Currently using marijuana (including medical marijuana) or has used marijuana (including medical marijuana) or cannabidiol oil within the last 1 year.
• Currently takes simple analgesics or NSAIDs >15 days per month or triptans, ergots, or combined analgesics >10 days per month for headaches or other body pain.
• Currently takes prescription opioids more than 2 days per month for headaches or body pain.
• Previous diagnosis of medication overuse headache, which has reverted to migraine within the last 3 months.
• Failed an adequate trial (2 months or greater), or based on the decision of the clinician, of at least 3 classes of a drug therapy for migraine prevention.
• Surgery for migraine prevention.
• Undergone nerve block (occipital or other) in the head or neck within the last 3 months.
• Received Botox or CGRP mAb injections within the last 6 months.
• Pregnant or thinking of becoming pregnant during the study period, or of childbearing years and unwilling to use an accepted form of birth control.
• Participating in any other therapeutic clinical investigation or has participated in a clinical trial in the preceding 30 days.
• Belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self- assessments is compromised (e.g., homeless, developmentally disabled, prisoner).
• A relative of or an employee of the Investigator or the clinical study site.
• Psychiatric or cognitive disorder and/or behavioral problems that, in the opinion of the clinician, may interfere with the study.
• Previously used gammaCore.