Medical necessity is the standard insurance plans use to decide whether a service is covered. In broad terms, a treatment is medically necessary when it is appropriate for the diagnosis, consistent with accepted standards of care, not primarily for convenience, and not more costly than an equally effective alternative. Each plan publishes its own medical policy documents that translate that principle into specific criteria for particular services, and those criteria can differ between carriers and change from year to year.
For outpatient psychiatry, medical necessity is rarely questioned for evaluations, medication management and psychotherapy when a diagnosis is documented. It becomes central for interventional treatments. A typical TMS policy requires a diagnosis of major depressive disorder of at least moderate severity, failure of two or more antidepressants from different classes at adequate dose and duration, or intolerance to them, and often a trial of psychotherapy. Spravato policies add that you must be on an oral antidepressant and that treatment occur in a certified REMS setting. Medicare applies similar standards through its local coverage determinations. Your psychiatrist's notes are what demonstrate necessity, which is why the first visit at Stedfast Psychiatry includes a detailed review of past medications, doses and responses. Keeping that history accurate protects your access to care if a plan asks for justification or if you later need prior authorization.