Your insurer denied the claim. Now what?

Insurers deny claims for reasons that range from legitimate to clerical to indefensible: a wrong code, a missing prior authorization, a service deemed 'not medically necessary' by someone who never examined you. The data on appeals is striking. A large share of denials that patients bother to appeal get overturned, yet only a tiny fraction of denials are ever appealed at all.

First, decode the denial

Your explanation of benefits (EOB) lists a denial reason code. The distinctions matter because each has a different fix.

• Administrative denials (wrong code, missing information) are usually fixed by the provider resubmitting the claim.
• Prior authorization denials can often be appealed with a letter from your doctor explaining urgency or necessity.
• Medical necessity denials require clinical evidence, and your physician's office is your strongest ally.
• Out-of-network denials may fall under the No Surprises Act if the care was emergency or at an in-network facility.

The internal appeal

You generally have 180 days to file an internal appeal. Request the insurer's complete claim file and the specific policy language they relied on; you are entitled to both. Your appeal letter should cite that language directly, attach supporting medical records, and include a letter of medical necessity from the treating physician. Send it by a trackable method and note every deadline.

The external review

If the internal appeal fails, federal law gives you the right to an independent external review for most denials involving medical judgment. An outside physician reviews the case, and the insurer is bound by the outcome. External reviews overturn insurers at a meaningful rate, and simply invoking the right often prompts an insurer to take a second, more careful look.

When to bring in help

Appeals are winnable but bureaucratic, and the insurer is counting on you giving up. If the amount is large, a professional advocate can run the appeal and, in parallel, negotiate the underlying hospital bill so you are protected regardless of which path resolves first.