How to Get Prior Authorization for TMS: Step-by-Step

What is prior authorization for TMS?

Prior authorization — sometimes called precertification or preapproval — means your insurance company reviews and approves TMS treatment before you start. Almost every insurer requires it.

Skip this step and your insurer can deny the entire claim after the fact. You’d owe the full amount. Don’t skip it.

Who handles the prior auth?

Usually, your TMS clinic does this for you. Good clinics submit dozens of these per month and know exactly what each insurer wants to see. Your job is making sure your psychiatrist has documented everything thoroughly.

If a clinic doesn’t handle prior auth? That’s a red flag. Find one that does.

Documentation your insurer will require

The prior auth package typically needs:

1. Psychiatric evaluation confirming Major Depressive Disorder (MDD)
2. Medication history — and this needs to be specific:
   • Name of each antidepressant tried
   • Dosage and how long you were on it
   • Why it was stopped (didn’t work, side effects, or both)
   • Most insurers require 2-4 failed trials (Aetna wants 4; most others want 2)
3. Current symptom severity on a validated scale (PHQ-9 is the most common)
4. Treatment plan from the TMS provider:
   • Which FDA-cleared device
   • Target brain region (typically left DLPFC)
   • Number of sessions requested (usually 36)
   • Session frequency and duration
5. Letter of medical necessity from your psychiatrist explaining why TMS is right for you

The prior authorization timeline

Some insurers move faster. UnitedHealthcare and Cigna tend to process within 7-10 days. Aetna and some BCBS plans take the full 15.

What happens during the review

Your insurer assigns a utilization management nurse or medical director to check your case against their clinical policy:

• Does the diagnosis qualify? (MDD is covered everywhere; OCD varies)
• Have you failed enough medications?
• Is the device FDA-cleared?
• Is the treatment plan within standard parameters?

If something’s missing, they’ll usually send a request for additional information instead of a flat denial. Respond fast. Delays here add weeks.

If your prior auth is approved

You’ll get an authorization number and a specified number of approved sessions.

A few things to know:

• Treatment must start within 30-60 days of approval
• Authorization usually covers 36 sessions. Maintenance sessions may need a separate auth
• Keep a copy of the approval letter. You may need it if billing disputes come up later

If your prior auth is denied

A denial is not the end. Roughly 30-50% of initial TMS denials are overturned on appeal.

Common denial reasons:

1. Not enough documented medication failures — the most frequent one by far
2. Missing or incomplete records — fixable by resubmitting with the right documentation
3. Diagnosis not covered — some plans only cover MDD, not OCD or other conditions
4. “Experimental” designation — rare for depression TMS in 2026, but it still pops up with some plans

The appeal process

Internal appeal (Level 1)

• File within 30-180 days of denial (check your plan’s specific deadline)
• Submit additional documentation: more detailed medication history, peer-reviewed studies, updated PHQ-9
• Request a peer-to-peer review. Your psychiatrist talks directly with the insurer’s medical director. This is often the single most effective step
• Decision within 30 days (standard) or 72 hours (expedited)

External appeal (Level 2)

• If the internal appeal fails, you have the right to an independent external review
• An outside physician — not affiliated with your insurer — reviews your case
• External reviews overturn denials in roughly 40-50% of cases
• File through your state insurance department or the insurer’s external review process

State insurance commissioner complaint

• If you believe the denial violates mental health parity laws, file a complaint with your state insurance commissioner
• This doesn’t replace the appeal process but it adds pressure and creates a paper trail

Tips for a smooth prior auth

1. Don’t wait until you’re desperate. Start the process as soon as TMS is recommended
2. Pick a clinic experienced with your insurer. They’ll know the specific criteria and common pitfalls
3. Tell your psychiatrist to document aggressively. “Tried and failed” needs dates, doses, and reasons
4. Request the insurer’s clinical policy. Ask for their TMS medical policy by name — then you know exactly what they require
5. Follow up weekly. Don’t assume no news is good news. Call and check
6. Keep records of every call. Date, name, reference number. Every single time

How to Get TMS Approved

What If You’re Denied?

For more details, see our Prior Authorization Guide and Denied Coverage Appeals guide.