Transcranial Magnetic Stimulation (TMS) is a non-invasive procedure that uses magnetic fields to stimulate nerve cells in the brain, offering a treatment option for individuals with Major Depressive Disorder (MDD). Medicare covers this outpatient therapy, but coverage strictly adheres to medical necessity and quantitative limits set by the Centers for Medicare and Medicaid Services (CMS). This ensures the treatment is applied appropriately to those who have not found relief through standard methods. The number of treatments covered is defined by a rigorous set of initial and subsequent coverage rules.
Meeting Medicare’s Criteria for TMS
To qualify for Medicare coverage of TMS, a patient must meet clinical criteria establishing medical necessity. The core requirement is a confirmed diagnosis of severe Major Depressive Disorder, documented by a Medicare-approved physician via a face-to-face examination. TMS is reserved for patients with treatment-resistant depression who have failed to achieve an adequate response from less invasive options.
The patient must demonstrate a lack of satisfactory improvement after a specific number of prior pharmacological trials. A common requirement is documentation of failure to respond to four trials of antidepressant medications in the current depressive episode, administered at or above the minimum effective dose. Some guidelines also require the patient to have failed a trial of evidence-based psychotherapy of adequate frequency and duration.
Patients must be free from contraindications that would make the procedure unsafe. These include magnetic-sensitive metal implants in or near the head, such as cochlear implants, pacemakers, or aneurysm clips. A history of seizures is another common exclusion criterion. Medicare does not cover TMS for other psychiatric conditions, such as moderate depression or generalized anxiety disorder, or if the patient is experiencing acute or chronic psychotic symptoms.
The Standard Number of Initial Treatments Covered
Medicare covers a predetermined number of sessions for the initial, acute treatment course once qualifying criteria are met. This initial phase is designed to induce remission or a significant response to treatment. The standard coverage allowance is for up to 30 treatment visits over approximately six weeks, plus an additional allowance for up to six tapering treatments immediately following the main course.
Patients are typically approved for a total of 30 to 36 sessions in the first block of therapy, usually administered once daily, five days a week. Continued coverage beyond this initial period depends on demonstrating a clinical response, typically measured using standardized rating scales for depressive symptoms. If a patient does not show sufficient clinical improvement after the first block, further coverage may be denied.
Initial authorization requires a written order from a psychiatrist who has examined the patient and reviewed their records. Medicare views this defined number of treatments as the necessary duration to test the therapy’s efficacy and achieve a meaningful outcome.
When Follow-Up and Maintenance Sessions Are Covered
After completing the initial course and achieving a positive response, Medicare may cover subsequent treatments if depressive symptoms return. These follow-up treatments are referred to as “retreatment,” not routine maintenance. Retreatment is considered medically necessary if the patient experiences a relapse of major depressive symptoms after having previously responded to TMS.
Coverage for a retreatment course requires documentation that the patient’s depressive symptoms have returned and that they previously demonstrated a significant response to the initial TMS therapy, often defined as a greater than 50% improvement on a standardized depression rating scale. The number of sessions covered in a retreatment course is generally more limited than the initial course. Some guidelines permit a second course of treatment, sometimes limited to 15 treatments, though the exact limits may vary by regional Medicare contractor.
Coverage for ongoing maintenance therapy, defined as routine, prophylactic treatments administered to prevent relapse, is not supported by current Medicare guidelines. This is because controlled clinical trial evidence supporting the long-term effectiveness of indefinite maintenance sessions is viewed as insufficient by the CMS. Therefore, additional sessions must be justified as treatment for a new depressive episode or a relapse, not simple preventative care.