Letter of Medical Necessity for Migraine: Is It Necessary?

For people with chronic migraine, a letter of medical necessity is a helpful document.

There are many care costs that go along with migraine: doctors’ visits, medications and both medical and nonmedical treatments. A letter of medical necessity (LMN) can help confirm that your costs are eligible expenses for a flexible spending account (FSA) reimbursement and are helpful to keep for tax purposes. We’ll walk you through what an LMN is, why you might need one, what it should include and where to get one.

What is a letter of medical necessity?

An LMN helps explain your migraine expenses. Your doctor will write this legal document. It confirms that services or items you bought were to diagnose, treat or prevent a disease or medical problem, such as migraine.

Expenses that are allowed can include office visits and hospital services. You can also get reimbursement for many types of tests, therapies and treatments—even transportation costs.

Migraine-related treatments that can get reimbursement include:

  • Medications
  • Supplements
  • Medical devices
  • Acupuncture
  • OnabotulinumtoxinA (Botox)
  • Exercise equipment
  • Fitness programs

You can review this list of eligible expenses to see if you need an LMN for your health-related expenses.

Why do people with chronic migraine need a letter of medical necessity?

An LMN is important because it explains your migraine-related expenses. According to Internal Revenue Service (IRS) rules, if you want to be reimbursed for certain expenses from a tax-free FSA or health savings account (HSA), your doctor may need to write an LMN. This letter is also helpful when your insurance company denies a claim and won’t cover a certain test or treatment.

An LMN is very useful for people with chronic migraine. Because they have many migraine attacks per month, they are more likely to use preventive treatments and require acute treatment more often.

What should a letter of medical necessity include?

Your healthcare provider must be the professional writing your LMN. It should include your name, your exact diagnosis and the recommended treatment. Your doctor should also note the recommended duration of treatment—that is, how long you need to receive treatment.

Your insurance company may want you to prove treatments were necessary when filing a claim. They may want your doctor to include treatments you tried before and to explain why they haven’t worked or were not continued. Clinical reasons with documents that support them may help. Supporting documents can include records, test results and peer-reviewed articles.

Finally, the letter should be signed by the healthcare provider. An LMN is valid for up to 12 months from the date it is written. If you need to extend treatment beyond 12 months, you’ll need to submit a new LMN. Keep in mind that submitting an LMN doesn’t mean it will get approval. If it is denied, you can submit a new LMN.

Where can I find a letter of medical necessity form?

You can submit an LMN in the form of a letter from your doctor’s office. It can be a doctor’s prescription written on a prescription pad or in the form of discharge papers. Here is a sample LMN form you can download if you want to see what it looks like and what information your healthcare provider will need to fill out.

If you receive certain treatments or have healthcare expenses, an LMN for migraine may help you get reimbursement. Talk to your doctor about writing an LMN for you and submit it with your claim for reimbursement.

The American Migraine Foundation is committed to improving the lives of those living with this debilitating disease. For more of the latest news and information on migraine, visit the AMF Resource Library. For help finding a healthcare provider, check out our Find a Doctor tool. Together, we are as relentless as migraine.

Reviewed for accuracy by the American Migraine Foundation’s subject matter experts, headache specialists and medical advisers with deep knowledge and training in headache medicine. Click here to read about our editorial board members.