Your Insurance Denied Your Claim. Here’s Exactly What to Do Next.

Getting a denial letter feels like a punch to the gut. You’re already dealing with a health issue, and now your insurance company is telling you they won’t pay for the care your doctor recommended. It feels final. It feels unfair. And it feels overwhelming.

Here’s what the insurance company doesn’t want you to know: that “no” is often just the opening of a negotiation. The data is clear—the vast majority of appealed denials get overturned. The system is designed to make you give up. Most people do. You don’t have to.

Key Takeaways

• 83% of prior authorization appeals result in the insurer overturning the denial

• Less than 1% of denied claims are ever appealed—meaning 99% of people accept “no” without question

• You have 180 days to file an internal appeal (6 months)

• 77% of denials are administrative errors, not medical judgments—and are often fixable

• External review is binding—if the independent reviewer sides with you, your insurer must accept it

The Numbers That Matter

Why Claims Get Denied (It’s Usually Not About You)

Before you spiral into anxiety, understand this: most denials are not a judgment about whether you deserve care. They’re often bureaucratic hiccups, coding errors, or missing paperwork.

According to industry data, 77% of all denials stem from administrative issues—not medical necessity decisions. That means three out of four denials could potentially be resolved by simply resubmitting with correct information.

The Three Types of Denials

Administrative Denials — 

High Success Rate

Rejected due to paperwork issues, not medical reasons. These are often the easiest to overturn.

• Incorrect procedure codes (CPT codes)

• Missing or incomplete patient information

• Claim filed after deadline

• Wrong insurance ID or group number

• Duplicate claim submission

Prior Authorization Denials — 

High Success Rate

The insurer didn’t pre-approve your treatment. 83% of these are overturned on appeal.

• Service required pre-approval you didn’t know about

• Insurer claims treatment isn’t “medically necessary”

• Insurer wants you to try cheaper alternatives first (“step therapy”)

• Treatment labeled “experimental” or “investigational”

Coverage Exclusion Denials — 

Variable Success

The insurer says your plan doesn’t cover this service. Harder to overturn, but not impossible.

• Service explicitly excluded from your plan

• Pre-existing condition limitations (rare under ACA)

• Out-of-network provider used without authorization

• Annual or lifetime limits reached

The First Step: Call and Ask Why

Before you do anything else, call the customer service number on your denial letter. Ask them to explain exactly why your claim was denied. Sometimes it’s a simple coding error that your doctor’s office can fix by resubmitting. Get the denial reason in writing and ask what specific information would be needed to approve the claim.

Your Step-by-Step Appeal Process

Step 1: Read Your Denial Letter Carefully

Your denial letter is required by law to include specific information. Look for:

• The specific reason for the denial (code or explanation)

• The deadline to file an appeal (usually 180 days)

• Instructions for how to appeal

• Your right to request your complete claim file

Step 2: Gather Your Documentation

Build your case with evidence. The stronger your documentation, the higher your chances of success.

• Copy of the denial letter

• Your insurance policy (specifically the section on covered benefits)

• Medical records related to the denied service

• A letter from your doctor explaining medical necessity

• Any research or clinical guidelines supporting the treatment

• Copies of all Explanation of Benefits (EOB) forms

Step 3: Get Your Doctor Involved

Your physician is your most powerful ally. Ask them to:

• Write a letter of medical necessity explaining why this treatment is required

• Include relevant clinical guidelines or peer-reviewed studies

• Document why alternative treatments won’t work for your case

• Conduct a peer-to-peer review with the insurance company’s medical director

Step 4: File Your Internal Appeal

Submit a formal written appeal to your insurance company. This is your “internal appeal”—the first official challenge.

• Write a clear, factual appeal letter (template below)

• Include all supporting documentation

• Send via certified mail with return receipt requested

• Keep copies of everything you send

• Note the date you submitted—the clock starts now

Step 5: Track Deadlines and Follow Up

Insurance companies have strict deadlines to respond. Hold them to it.

• If you haven’t received treatment yet: 30 days for a decision

• If you’ve already received treatment: 60 days for a decision

• For urgent/emergency care: 72 hours for a decision

• Call to confirm receipt within 5 business days of sending

Step 6: Request External Review (If Denied Again)

If your internal appeal is denied, you have the right to an external review by an independent third party.

• The external reviewer is not employed by your insurance company

• You have 60 days after final internal denial to request this

• The external reviewer’s decision is binding—your insurer must accept it

• External reviews have approximately a 44% success rate

Appeal Timeline: What to Expect

Appeal Letter Template

Use this template as a starting point. Customize it with your specific details and situation.

[Your Name]

[Your Address]

[City, State ZIP]

[Date]

[Insurance Company Name]

[Appeals Department Address]

[City, State ZIP]

Re: Appeal of Claim Denial

Member ID: [Your Member ID]

Claim Number: [Claim Number from Denial Letter]

Date of Service: [Date of Denied Service]

Dear Appeals Department:

I am writing to formally appeal the denial of coverage for [name of procedure/treatment/medication] that I received on [date]. According to your denial letter dated [date], this claim was denied because [quote the reason from the denial letter].

I am requesting that you reverse this decision for the following reasons:

[Explain why the treatment was medically necessary. Be specific. Reference your doctor’s recommendation and any clinical guidelines that support this treatment for your condition.]

Enclosed please find the following supporting documentation:

1. Letter of medical necessity from my treating physician, Dr. [Name]

2. Relevant medical records documenting my condition

3. [Any additional documentation: clinical studies, treatment guidelines, etc.]

According to my plan documents, [reference the specific section that shows this should be covered]. This treatment meets the criteria for coverage under my plan.

I respectfully request that you review this information and reverse your denial. Please respond within the timeframe required by law. If you have any questions, I can be reached at [phone number].

Sincerely,

[Your Signature]

[Your Printed Name]

Enclosures: [List all documents you’re including]

cc: [Your Doctor’s Name], [State Insurance Commissioner — optional but powerful]

Pro Tip: Copy Your State Insurance Commissioner

When you cc your state’s Department of Insurance on your appeal letter, insurance companies often take it more seriously. It signals you know your rights and are prepared to escalate. Find your state insurance commissioner at naic.org

When to Escalate: Your Additional Options

If your internal and external appeals are denied, you still have options:

Your Appeal Checklist

Before You Submit

• Read the denial letter and noted the specific reason for denial

• Called insurance company to understand the denial and ask what’s needed

• Requested complete claim file from insurance company

• Obtained letter of medical necessity from my doctor

• Gathered all relevant medical records

• Reviewed my plan documents for coverage language

• Written a clear, factual appeal letter

• Made copies of everything before sending

• Sending via certified mail with return receipt

• Noted the deadline for insurance company to respond

The Bottom Line

Insurance denials are designed to make you give up. The appeals process is intentionally complex and time-consuming. Insurance companies know that most people won’t fight back—and that’s exactly what they’re counting on.

But the data tells a different story. When people do appeal, they win far more often than they lose. An 83% success rate on prior authorization appeals isn’t luck—it’s evidence that many denials shouldn’t have been issued in the first place.

You have rights. You have options. And now you have a roadmap.

This Feels Like Too Much?

We get it. You’re dealing with a health issue and the last thing you need is to become a paperwork expert. That’s exactly why we exist. Let us handle your appeal while you focus on what matters—your health.

Let Us Handle Your Appeal →

Sources

1. KFF. “Claims Denials and Appeals in ACA Marketplace Plans in 2023.” kff.org

2. American Medical Association. “Over 80% of prior auth appeals succeed. Why aren’t there more?” ama-assn.org

3. Experian Health. “State of Claims Report 2025.” experian.com

4. HealthCare.gov. “How to appeal an insurance company decision.” healthcare.gov

5. American Hospital Association. “Payer Denial Tactics — How to Confront a $20 Billion Problem.” aha.org

6. National Association of Insurance Commissioners. “How to Appeal Denied Claims.” naic.org

7. Washington State Office of Insurance Commissioner. “Common reasons for a denial and examples of appeal letters.” insurance.wa.gov

8. Counterforce Health. “Insurance Denial Statistics: Why 80% of Appeals Succeed.” counterforcehealth.org

MedicalBills.com Research Team