Denied by your insurance? You have 180 days and a real shot.
About 1 in 5 in-network claims gets denied, and fewer than 1 in 100 denials is ever appealed. But when people do appeal, roughly a third win at the first level, and the odds get better from there. Enter the date on your denial letter and get your fight plan: your deadline, your next move, and what the bill is worth.
Your Fight Plan
Health Insurance Claim Denial · 2026 rules
What date is on your denial letter?
It is printed at the top of the letter. Your appeal deadline is counted from that day, not from the day you read it.
Frequently Asked Questions
Why did my insurance deny my claim?
The most common reasons are that a reviewer decided the care was not medically necessary, the provider was out-of-network, the service is excluded from your plan, prior authorization was missing, or a code on the bill was wrong. Read the exact reason on your Explanation of Benefits, because it decides your move. Medical-necessity and prior-auth denials are yours to appeal with evidence. Coding and billing errors are the provider’s job to fix, and you should not pay them.
How do I appeal a health insurance denial?
File an internal appeal in writing with your insurer, within 180 days of the denial notice. Ask, in writing, for the full claim file and the clinical criteria they used, which federal law gives you for free, then attach a letter of medical necessity from your doctor. File before the deadline even if your evidence is not complete, because you can add to it after.
What is external review?
External review is the stage after your internal appeal, where an independent doctor with no stake in your case re-decides it. Their decision is binding on the insurer, so the insurance company no longer gets the final say. You have 4 months from your final internal denial to request it, and standard reviews are decided within 45 days. This is the stage where the odds get better, and almost nobody reaches it.
Does appealing actually work?
Often, yes. In 2024, insurers overturned about 34% of internal appeals in the patient’s favor, and state external-review programs overturn roughly 4 to 5 in 10. The catch is that fewer than 1 in 100 denials is ever appealed, so most denied money is simply left on the table. One letter has about a 1 in 3 chance of erasing the bill before you even escalate.
How long do I have to appeal a health insurance denial?
At least 180 days from the date you got the denial notice to file your internal appeal, under federal law. Some plans allow longer, so the deadline printed on your own denial letter is the one that governs your plan. If your internal appeal is denied, you then have 4 months from that final denial to request an external review. Verbal denials do not start these clocks, so always get the decision in writing.