How to appeal a denied health insurance claim

A denial letter reads like a final answer. It usually isn't. It is the insurer's first decision, and the law gives you at least two more chances to change it: an internal appeal to the insurer, and, if that fails, an external review by someone the insurer does not employ.

Here is how to work through both without losing track. This isn't legal advice, and your plan's own documents set the exact rules, but the steps below apply to most plans under the Affordable Care Act.

Start with the reason code

Find the denial reason on the letter or on the Explanation of Benefits. It is usually a short code with a line of text. The reason decides your whole strategy, and most fall into a few buckets:

• Not medically necessary. The insurer doesn't think the care was needed. You answer with clinical evidence.
• Prior authorization missing. Approval wasn't requested in advance. Sometimes the provider can request it retroactively.
• Out of network or not covered. Check your plan document to see whether that is actually true.
• Coding or paperwork error. A wrong code or missing information. Often the provider's billing office can fix and resubmit this faster than any appeal.

Call the insurer and ask two questions: "What exactly would change this decision?" and "Can you send me the full claim file and the criteria you used?" You are entitled to see the information the decision was based on.

Build the appeal

For medical-necessity denials, the most important document is a letter of medical necessity from the treating doctor. Ask the office for one and say what it should cover: your diagnosis, what was tried before, why this treatment was the right next step, and what is likely to happen without it. Doctors write these often. A specific request gets a better letter.

Then write your own cover letter. Keep it to one page:

1. Your name, member ID, claim number, date of service.
2. One sentence: "I am appealing the denial of [service] dated [date]."
3. Why the denial is wrong, tied to the reason code.
4. A list of what is enclosed: the doctor's letter, relevant records, the denial letter.

The appeal that wins is rarely the angriest one. It is the one that answers the exact reason on the denial, with evidence attached.

Know the clocks

For plans covered by the ACA rules, you have 180 days from the denial notice to file an internal appeal, according to HealthCare.gov. For care you have already received, the insurer must decide within 60 days. If your situation is urgent, say so: urgent appeals are decided much faster, and you can request an external review at the same time.

If the internal appeal is denied, you can request an external review within 4 months of that final denial. An independent reviewer decides, standard reviews finish within 45 days, and the insurer is required to accept the result. Your state insurance department or HealthCare.gov can tell you which process your plan uses.

Keep a paper trail

Every appeal is won or lost on documentation, so treat it like a file:

• Send everything in a way that proves delivery, and keep copies.
• Log every phone call: date, name, reference number, what was said.
• Put the deadlines on your calendar the day the letter arrives.

EOB Keeper helps with the tracking side. It scans your EOBs and provider bills on your iPhone, pairs them, and flags charges above what the EOB allowed, which is often how you notice a denial in the first place. Its appeal calendar sends local reminders at 90, 30 and 7 days before a 120-day dispute deadline, and it keeps a per-member archive you can export as a PDF. It is free, with no account. If EOBs are new to you, start with how to read one.

Denials are common. So are successful appeals, for the people who send one.