Health Insurance Claim Denied? 2025 Appeal Guide & Free Letter

A denied medical bill is one of the most stressful things you can experience. You're already dealing with a health issue, and now you have a financial battle on top of it.

Medical bills are the leading cause of bankruptcy in the U.S., but millions of dollars in denied claims are overturned every year.

Whether it's a surgery, an MRI, or an emergency room visit, insurance companies often deny first and ask questions later. You have the right to appeal, and the odds are better than you think.

Top Reasons Health Insurance Claims Get Denied

1. "Not Medically Necessary"

This is the most common subjective denial. An insurance doctor (who never saw you) decided you didn't need the treatment your actual doctor prescribed.

The Fix: You need a letter of medical necessity from your doctor citing *Standard of Care* guidelines (like Milliman or InterQual) that they followed.

2. Missing Prior Authorization

You got the procedure, but "forgot" to ask for permission first.

The Fix: If it was an emergency, the No Surprises Act protects you—prior auth is not required for true emergencies. If it wasn't, appeal by showing that the approval *would have been granted* if asked, known as a "retroactive authorization."

3. Coding Errors (The "Quick Win")

Sometimes a simple typo in the CPT (procedure) code or ICD-10 (diagnosis) code triggers an automatic denial.

The Fix: Call your doctor's billing office and ask for meaningful review. A corrected claim can be processed in days.

4. Out-of-Network Surprise Bills

You went to an in-network hospital but saw an out-of-network anesthesiologist.

The Fix: The No Surprises Act bans this practice for many facility-based providers. You should only pay your in-network copay.

The 3 Levels of Health Insurance Appeals

Reconsideration (Peer-to-Peer): Your doctor talks to the insurance company's doctor. This is the fastest way to solve "Medical Necessity" disputes.
Level 1 Appeal: A formal internal review by the insurance company.
External Review: If they deny you again, you can demand a review by an independent third party (IRO). Insurers lose ~40-50% of these.

How to Write a Winning Appeal

Be Objective: Don't just say "I need this." Say "This treatment meets the clinical criteria for condition X."
Submit the Whole Chart: Don't assume they have your records. Send the operative report, lab results, and physician notes yourself.
Use Our Tool: Our Appeal Letter Generator cites specific regulations based on your denial type.

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Expert Insight

Nurse Auditor Secret: Initial claims are often reviewed by software or overworked nurses who spend less than 3 minutes per file. They look for keywords. If your doctor captures the "magic words" from the clinical policy bulletin in their notes, the claim gets paid.

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Your Action Plan

Follow these steps in order:

Call your insurer found out the exact 'Denial Code'

Request your 'Explanation of Benefits' (EOB)

Ask your doctor for a 'Peer-to-Peer' review request

Check if your employer's plan is 'Self-Funded' (different rules apply)

Generate your appeal letter immediately

Frequently Asked Questions

Do I have to pay the bill while appealing?▼

Generally, no. Contact the provider and tell them the claim is 'in dispute/appeal.' Ask them to freeze the account so it doesn't go to collections.

How long do I have?▼

Usually 180 days from the date on the EOB. Do not wait.

What if it's an emergency room bill?▼

The 'Prudent Layperson Standard' applies. If a reasonable person would think it was an emergency (e.g., chest pain), they must cover it, even if it turned out to be indigestion.