My Insurance Was Denied — What Are My First Steps?

Getting an insurance denial can feel like a punch to the gut — especially when the treatment or reimbursement matters for your health or finances. But a denial is not the end. It is the beginning of a process, and how quickly and carefully you respond in the first few days makes a significant difference in your outcome.

Here are your first steps.

Step 1: Read the Denial Letter Carefully

Your insurer is legally required to send you a written denial that includes:

• The specific reason for the denial
• The policy provision, exclusion, or clinical criterion relied upon
• Instructions on how to appeal
• The deadline to file an appeal

Read every word. The denial reason tells you exactly what you need to argue. Common reasons include: "not medically necessary," "Prior Authorization Denied: How to Appeal" class="auto-link">prior authorization not obtained," "non-covered service," "out-of-network provider," or "experimental treatment."

eob">Step 2: Request Your Explanation of Benefits (EOB)

If you haven't received your EOB yet, log in to your member portal or call your insurer to get it. The EOB shows the denial reason code in more detail and confirms what was billed, what was allowed, and what (if anything) was paid.

Step 3: Note the Appeal Deadline Immediately

This is critical. Most health plans give you 180 days from the date of the denial notice to file an internal appeal. Some plans are stricter. Write this date down and set a calendar reminder.

Missing the appeal deadline can permanently waive your right to contest the denial — at least through the standard process.

Step 4: Pull Your Policy Documents

Find your Summary of Benefits and Coverage (SBC) and your plan's full Summary Plan Description (SPD) or Certificate of Coverage. Look up the benefit or service that was denied. Understand exactly what your plan covers, what it excludes, and what the authorization requirements are.

If the insurer denied based on a clinical criteria document (like InterQual or Milliman guidelines), you can request a copy of that criteria under ERISA or ACA disclosure rules.

Step 5: Contact Your Doctor's Office

Your treating physician is your most valuable ally. Their office can:

• Write a letter of medical necessity explaining why the treatment is appropriate
• Provide clinical documentation (treatment notes, test results, specialist referrals)
• Request a peer-to-peer review — a direct call between your doctor and the insurer's medical reviewer that sometimes reverses denials before a formal appeal is even needed

Call the billing department and the clinical team. Tell them you received a denial and ask what they can provide to support an appeal.

Step 6: Request the Insurer's Complete Claim File

Under the ACA and ERISA, you are entitled to copies of all documents the insurer relied upon in making its determination. This includes any clinical review notes, the specific guidelines used, and any internal communications. Send a written request and keep a record.

Reviewing this file often reveals errors — for example, the reviewer may have overlooked a diagnosis code, applied the wrong year's guidelines, or never received a key piece of documentation.

Step 7: Write and Submit Your Appeal

With your denial reason, physician letter, supporting documentation, and policy language in hand, write a formal appeal letter. Be specific: address the exact denial reason, cite your policy language, reference clinical evidence, and explain clearly why the denial is incorrect.

Submit by certified mail or through your insurer's online portal — and keep copies of everything.

Step 8: Escalate if Needed

If your internal appeal is denied:

• Request External Independent Review: Complete Guide" class="auto-link">external review by an IROs) Explained" class="auto-link">Independent Review Organization — it's free and binding on your insurer.
• File a complaint with your state insurance commissioner.
• Contact a patient advocate or insurance attorney if the stakes are high.

Fight Back With ClaimBack

ClaimBack guides you through every one of these steps — from decoding your denial letter to generating a customized appeal — so you never have to figure it out alone.

Start your appeal at ClaimBack

Related Reading

• How to Write an Insurance Appeal Letter
• Internal vs. External Insurance Appeal: What's the Difference?
• Common Reasons Insurance Claims Are Denied