How to Appeal an Insurance Denial (Step-by-Step Guide)

Getting a denial letter from your insurance company is frustrating — but it is not the end. In fact, 54% of insurance denials are overturned on appeal when patients take the right steps. This guide walks you through exactly what to do.

Step 1: Understand Why Your Claim Was Denied

The denial letter must include a reason. Common reasons include:

• Not medically necessary — the insurer does not believe the treatment is required
• Prior authorization required — your doctor did not get pre-approval
• Out of network — the provider is not in your plan
• Experimental or investigational — the treatment is not standard of care
• Coding error — a billing code was entered incorrectly

Read your denial letter carefully and identify the exact reason. This will determine your appeal strategy.

Step 2: Know Your Deadlines

Most insurance plans require you to file an appeal within 30 to 180 days of receiving the denial. Check your denial letter for the exact deadline. Missing it means losing your right to appeal.

Step 3: Gather Supporting Documentation

A strong appeal needs evidence. Collect:

• Your denial letter
• Medical records supporting the treatment
• A letter of medical necessity from your doctor
• Relevant clinical guidelines (AMA, CMS, specialty societies)
• Any prior authorizations or referrals

Step 4: Write a Professional Appeal Letter

Your appeal letter is the most important part. It must:

• Clearly state you are appealing the denial
• Reference your policy number and claim number
• Explain why the denial is incorrect using medical evidence
• Cite clinical guidelines and medical literature
• Include your doctor's supporting statement

Writing this letter can take hours if you do not know what to include. AppealRx generates this letter for you in under 60 seconds, using the same language and citations that get approvals.

Step 5: Submit Your Appeal

Send your appeal by certified mail or through your insurer's online portal. Keep copies of everything. Note the date you submitted.

Step 6: If the Internal Appeal Fails

If your insurer denies your internal appeal, you have the right to an external review by an independent organization. Under the ACA, this is your legal right for most health plans. The external reviewer's decision is binding on the insurer.