This site collects the letters that actually move a denial — the internal appeal, the ERISA request for your claim file, the expedited route when care is urgent, the external/independent review, and appeals written for the specific reason you were denied (medical necessity, prior authorization, step therapy, out-of-network, and more) — each with what to attach, the deadline to watch, and the rule it relies on.
Every letter is a starting template. Nothing here is legal, medical, or insurance advice, and using a template creates no professional relationship. For complex or urgent denials, talk to a patient advocate or attorney.