A denied health insurance claim can feel final when you see “not covered” or “payment denied” on an Explanation of Benefits. Often, it is not. Most private U.S. health plans have an appeal process that lets you challenge the decision, add evidence, and ask for a fresh review. The strongest appeals are organized, specific, and tied to the insurer’s stated reason for denying the claim.
This guide focuses on private U.S. health insurance. Medicare, Medicaid, and some specialized plans use different appeal systems; follow your denial notice.
Start With the Exact Denial Reason
Read the denial notice and Explanation of Benefits carefully. Identify the claim number, date of service, amount denied, reason code, and any plan provision the insurer says applies. Common reasons include missing prior authorization, coding errors, insufficient medical-necessity documentation, out-of-network restrictions, or a service the plan considers excluded.
Not every denial needs a formal appeal. If the problem is a billing code, missing record, or incomplete claim, your provider’s billing office may be able to correct and resubmit it. That can be faster than entering the full insurance appeal process.
Check the Deadline Immediately
For many private health plans covered by federal appeal protections, you have at least 180 days from receiving the denial notice to file an internal appeal. Your plan may allow longer, but the denial letter is the document to follow. Mark the deadline and aim to submit well before it.
If delaying care could seriously threaten your health or your ability to regain maximum function, ask about an expedited appeal. In qualifying urgent cases, an external review may sometimes be requested while the internal appeal is still underway.
Build a Clear Appeal File
Keep all records in one folder. Include the denial letter, Explanation of Benefits, relevant policy language, bills, medical records, prior-authorization information, referrals, and notes from calls with the insurer. Record dates, representative names, and reference numbers whenever you speak with the plan.
If medical judgment is involved, ask your doctor for a concise supporting letter. It should explain the diagnosis, why the treatment was medically necessary, what alternatives were tried or considered, and why the requested service fits your clinical situation. You can also ask the insurer for documents and records relevant to the claim; employer-sponsored plans subject to ERISA generally must provide relevant claim records on request.
Match the evidence to the denial
Your appeal should answer the insurer’s stated reason directly. If the denial says the care was not medically necessary, focus on clinical notes, test results, treatment history, and the plan’s medical-necessity criteria. If it says prior authorization was missing, gather the authorization number, referral, portal message, call record, or evidence supporting an exception.
Write a Focused Internal Appeal
Start with your name, member ID, claim number, provider, date of service, and the decision you are appealing. Then explain why you believe the denial is incorrect under the plan terms. Refer to your supporting documents by date or name so the reviewer can follow your argument quickly.
A useful approach is to cover five points: what happened, why the claim was denied, what evidence challenges that reason, what policy language supports coverage, and what outcome you want. Ask clearly for the denial to be reversed and the claim reprocessed, or for the requested service to be approved.
A practical example
Suppose an MRI is denied as not medically necessary. A weak appeal says only that you were in pain and needed the scan. A stronger appeal includes the physician’s examination findings, records showing conservative treatment failed, the imaging order, and a doctor’s letter connecting those facts to the plan’s criteria. That gives the reviewer a documented basis to overturn claim denial rather than simply a request for sympathy.
Submit the Appeal in a Trackable Way
Use the delivery method listed in the denial notice. If you submit online, save the confirmation page or reference number. If you mail the appeal, use a trackable service. If you fax it, keep the transmission report. Save a complete copy of everything you send.
After submission, confirm that the plan received it. For many ACA-protected appeals, the insurer generally has up to 30 days to decide an appeal involving a service you have not yet received and up to 60 days for a service you already received. Urgent appeals follow much faster timelines.
If the Appeal Is Denied, Look at External Review
An external review moves the dispute outside the insurance company to an independent reviewer. It may be available for certain denials involving medical judgment, including medical necessity or treatment considered experimental or investigational, as well as some rescissions of coverage. Availability depends on the plan, denial type, and the state or federal process that applies.
Under the HHS-administered federal process, a request generally must be filed within four months after receiving the relevant denial or final internal decision. Standard reviews are generally completed no later than 45 days after the request is received. Expedited reviews can be much faster when the medical circumstances qualify. Your final denial should explain how to start the correct external review health claim process.
If an independent reviewer reverses a denial in a binding external review, the insurer must follow that decision.
Get Help When the Case Is Complicated
Your doctor’s office can help with records and medical-support letters. A state Consumer Assistance Program or Department of Insurance may help explain appeal rights. People with employer-sponsored coverage can also contact the U.S. Department of Labor’s Employee Benefits Security Administration. Complex or high-value disputes may justify speaking with a qualified attorney.
Natural internal-link opportunities for this article include common reasons health insurance claims are denied, how to read an Explanation of Benefits, and how medical necessity affects health insurance coverage.
FAQ
How long do I have to appeal a denied health insurance claim?
Many private health plans give you at least 180 days from the denial notice to request an internal appeal. Your exact deadline may differ, so follow the date and instructions in your own notice.
Can my doctor appeal the denial for me?
Often, yes. A provider or another authorized representative may be able to appeal on your behalf, although the plan may require a signed authorization form. Keep your own copies and track the deadline even if the provider handles the paperwork.
What happens if my internal appeal is denied?
You may qualify for an independent external review, depending on the denial and your plan. The final internal decision should explain whether external review is available and where to file the request.
Does an appeal guarantee payment?
No. An appeal gives you a formal opportunity to challenge the decision, but it does not guarantee a reversal. A well-supported appeal is stronger when it addresses the exact denial reason with plan language, medical evidence, and complete records.
Make the Appeal Easy to Approve
Move quickly, but do not rush the evidence. Confirm the deadline, identify the denial reason, gather documents that answer that reason, and submit a concise request for the decision to be reversed. If the insurer upholds the denial, review your external-review rights promptly. A denial may be the start of the process rather than the final word.