How to Appeal a Health Insurance Claim Denial (Template Included)

You open an envelope from your insurance company. There it is: "Claim Denied." Two words that can make your stomach drop, especially when you're already dealing with the stress of a medical issue.

Here's the good news: a denied claim is not a final answer. It's the beginning of a conversation — one you can win. Studies show that roughly 50% of internal appeals and up to 60% of external appeals are decided in the patient's favor. Yet fewer than 1 in 100 denied claims ever gets appealed.

That means insurance companies are counting on you to give up. This guide will make sure you don't.

Why Claims Get Denied (and Why It's Often Wrong)

Before you can fight a denial, you need to understand why it happened. Here are the most common reasons:

1. "Not Medically Necessary"

This is the big one. Your insurer decided the treatment your doctor ordered wasn't needed. Sometimes a reviewer hundreds of miles away — who has never examined you — overrides your doctor's judgment. Under the Affordable Care Act, you have the right to challenge this.

2. Prior Authorization Wasn't Obtained

Many procedures require pre-approval. If your provider didn't get it (or got it late), the claim gets denied. The frustrating part: this is often an administrative error by the provider's office, not anything you did wrong.

3. Out-of-Network Provider

You saw a provider outside your plan's network. Sometimes this is your choice; often it happens without your knowledge — like when an in-network hospital uses an out-of-network anesthesiologist. The No Surprises Act now protects you from many of these surprise bills.

4. Coding Errors

Medical billing uses thousands of codes. A single wrong digit can turn a covered procedure into a denied one. Requesting an itemized bill can help you spot these errors.

5. Service Not Covered

Your plan simply doesn't cover the service. This is the hardest to overturn, but even here you have options — especially if the service is considered an essential health benefit under the ACA.

6. Filing Deadline Missed

Claims submitted after the filing deadline get auto-denied. This is usually on the provider, not you.

Step 1: Read Your Denial Letter Carefully

Your denial letter (technically called an "Explanation of Benefits" or "Adverse Benefit Determination") is required by law to include:

• The specific reason for the denial
• The plan provision or rule they're citing
• Instructions for how to appeal
• The deadline to file your appeal (usually 180 days for internal appeals)
• Your right to request the complete claim file

Key takeaway: Don't throw this letter away. Highlight the denial reason and the appeal deadline. Everything you do from here builds on what this letter says.

Step 2: Call Your Insurance Company

Before you write anything, call the number on your denial letter. Ask:

• "Can you explain exactly why this was denied?"
• "What specific plan language or medical policy supports this denial?"
• "What documentation would you need to overturn this?"
• "Is there a peer-to-peer review option for my doctor?"

Write down the name of every person you speak with, the date, and what they said. This creates a paper trail.

Sometimes a simple call resolves the issue — especially if the denial was due to a coding error or missing information. If the representative can reprocess the claim, ask for a reference number.

Step 3: Get Your Doctor on Your Side

Your doctor is your most powerful ally. Contact their office and explain the denial. Ask them to:

• Write a letter of medical necessity explaining why the treatment was needed
• Request a peer-to-peer review with the insurance company's medical director
• Provide any clinical documentation that supports the treatment
• Reference clinical guidelines or medical literature

Peer-to-peer reviews — where your doctor speaks directly with the insurer's doctor — resolve many denials before you even need to file a formal appeal. About 75% of peer-to-peer reviews result in the denial being overturned.

Step 4: File an Internal Appeal

If the phone call doesn't work, it's time to file a formal internal appeal. Under the ACA, every health plan must offer at least one level of internal appeal, and they must decide within:

• 72 hours for urgent care situations
• 30 days for pre-service claims (before treatment)
• 60 days for post-service claims (after treatment)

What to Include in Your Appeal

1. Your appeal letter (template below)
2. A copy of the denial letter
3. Your doctor's letter of medical necessity
4. Relevant medical records
5. Clinical guidelines or studies supporting the treatment
6. Any correspondence with the insurance company

Send everything by certified mail with return receipt so you have proof of delivery. Also keep copies of everything you send.

Step 5: Appeal Letter Template

Here's a template you can adapt for your situation. Replace the bracketed sections with your information:

Step 6: If Internal Appeal Fails — Go External

If your internal appeal is denied, you have the right to an external review. This is where an independent third party — not employed by your insurance company — reviews your case.

External reviews are powerful. The reviewer is an independent medical expert in the relevant specialty. They have no financial incentive to deny your claim. And their decision is binding on the insurance company — if they rule in your favor, the insurer must pay.

How to request an external review:

• Your denial letter should include instructions for requesting external review
• You typically have 4 months from the final internal denial
• For urgent situations, you can request an expedited external review that must be decided within 72 hours
• The external review is usually free to you

Step 7: Bring in Reinforcements

If you're struggling with the process, you don't have to do it alone:

Your State Insurance Department

Every state has a Department of Insurance that handles consumer complaints. Filing a complaint doesn't replace an appeal, but it puts regulatory pressure on the insurer. Some states have dedicated consumer assistance programs that will help you through the appeal process for free.

Your Employer's HR Department

If you have insurance through work, HR can be a powerful advocate. They're the insurance company's client, and insurers want to keep employer accounts happy.

Patient Advocates

Professional patient advocates specialize in fighting insurance denials. Some charge fees; others work on a contingency basis (they get paid only if you win). Organizations like the Patient Advocate Foundation offer free assistance.

Your State Attorney General

For patterns of bad behavior — especially if you believe the denial violates state law — filing a complaint with the AG's office can escalate the issue.

Special Situations

Emergency Care Denials

Under the prudent layperson standard, insurance must cover emergency care if a reasonable person would believe they were experiencing an emergency — regardless of the final diagnosis. If your ER visit was denied because it "wasn't really an emergency," you have strong grounds for appeal. Learn more about ER visit costs and your rights.

Mental Health Denials

The Mental Health Parity and Addiction Equity Act requires insurers to cover mental health and substance abuse treatment at the same level as physical health. If your therapy or mental health treatment was denied, check whether the denial violates parity requirements.

Prescription Drug Denials

If a medication was denied, ask your doctor about filing an exception request or step therapy override. Your doctor can argue that formulary alternatives aren't appropriate for your situation. See our guide on getting prescription drugs for less.

Timeline: What to Expect

5 Pro Tips to Strengthen Your Appeal

1. Use the insurer's own language against them. Quote your plan document. If they say something isn't covered, find where it says it is (or where it doesn't explicitly exclude it).
2. Reference clinical guidelines. Medical societies publish treatment guidelines. If your treatment aligns with published standards of care, cite them specifically.
3. Be factual, not emotional. Your appeal letter should read like a legal brief, not a complaint letter. State facts. Reference documentation. Make it easy for the reviewer to say yes.
4. Request your complete claim file. You have the legal right to see everything in your file, including the insurer's internal notes and the criteria they used. This sometimes reveals errors in their review process.
5. Don't pay the bill until the appeal is resolved. You can't be sent to collections while an appeal is pending. If a provider threatens collections during your appeal, know your rights.

What If You Owe Money After Everything?

If your appeal is ultimately unsuccessful, you still have options:

• Negotiate directly with the provider. Many hospitals and doctors will reduce bills or set up payment plans. Start by requesting an itemized bill to check for errors.
• Ask about financial assistance. Nonprofit hospitals are required to have charity care programs. You might qualify even with insurance.
• Use Taven's bill review tool to check whether you're being charged a fair price compared to what other patients pay for the same service.
• Compare costs for future care. Use Taven's Compare Care tool to find fair prices before your next procedure.

The Bottom Line

A denied claim is a starting point, not an ending. Insurance companies deny claims knowing that most people won't fight back. But the appeal process exists for a reason, and the odds are surprisingly in your favor when you use it.

Here's your action checklist:

1. Read the denial letter and note the reason and deadline
2. Call the insurer and ask what it would take to overturn it
3. Get your doctor to write a letter of medical necessity
4. File a formal internal appeal with supporting documentation
5. If denied again, request an external review
6. Bring in your state insurance department or a patient advocate if needed

You have rights. Use them.