A denied claim or prior authorization can feel like a dead end. It isn’t. Under the Affordable Care Act, you have the right to an internal appeal with your insurer and, if that fails, an external review by an independent organization. Many people never appeal — but those who do often succeed.
Key takeaways
- Find out the exact reason for the denial — many are simple coding or paperwork errors.
- You generally have 180 days from the denial notice to file an internal appeal.
- Urgent care appeals must be decided quickly — often within 72 hours.
- If the internal appeal fails, request an external review; the insurer must follow its decision.
Common reasons claims are denied
- Billing or coding errors by the provider
- Missing prior authorization
- “Not medically necessary”
- Out-of-network provider
- Service not covered by the plan
- Missing information or eligibility issues
Start by reading the denial letter and your Explanation of Benefits, then call your insurer and the provider. Coding errors can often be fixed by the provider resubmitting the claim — no appeal needed.
Step 1: File an internal appeal
- Check the deadline. Generally 180 days from the denial notice for ACA-compliant plans.
- Request your claim file and the plan’s criteria for the decision — you’re entitled to them free.
- Get a letter from your doctor explaining why the treatment is medically necessary, citing your history and guidelines.
- Write your appeal letter (see the checklist below) and send it with supporting documents.
- Keep copies and send by a method you can track.
Insurers generally must decide within 30 days for services you haven’t received yet, 60 days for services already received, and as fast as your condition requires — often 72 hours — for urgent care.
Step 2: Request an external review
If your internal appeal is denied, you can ask for an external review by an independent review organization — generally within 4 months of the final denial. The reviewer’s decision is binding on the insurer. Urgent situations can get an expedited external review, sometimes at the same time as the internal appeal. Your denial letter must explain how to request it.
Appeal letter checklist
- Your name, member ID, claim number and date of service
- A clear statement: “I am requesting an appeal of the denial of [service].”
- Why you believe the denial is wrong, point by point
- Your doctor’s letter of medical necessity
- Relevant medical records, test results and clinical guidelines
- The plan language that supports coverage, if you can find it
- A request for a decision within the required time frame
Free help: Many states have a Consumer Assistance Program or insurance department that helps with appeals at no cost. Employer self-funded plans are overseen by the U.S. Department of Labor, which also offers help.
Example
Sam’s insurer denied an MRI as “not medically necessary.” He requested the plan’s criteria and learned they required six weeks of physical therapy first. His records showed he’d completed eight weeks, but they hadn’t been sent with the request. His doctor resubmitted with the therapy notes and a short letter, and the appeal was approved within two weeks.
Frequently asked questions
Should I pay the bill while I appeal?
Tell the provider you’re appealing and ask them to hold the bill. Many will pause collections while an appeal is pending. Get the agreement in writing.
Can my doctor appeal for me?
Yes. You can authorize your doctor or another representative to file on your behalf. For prior authorization denials, doctors can often request a “peer-to-peer” review with the insurer’s medical reviewer.
Do these rules apply to Medicare?
Medicare and Medicare Advantage have their own five-level appeals process with different deadlines. Your Medicare Summary Notice or plan notice explains the steps.
What if my plan is grandfathered or self-funded?
Some older “grandfathered” plans don’t have to follow all ACA appeal rules, and self-funded employer plans follow federal ERISA rules. Check your plan documents or ask HR.
Related: Can’t pay a medical bill? · Surprise medical bills
Sources: HealthCare.gov (“Appealing a health plan decision”); U.S. Department of Labor; CMS. Deadlines vary by plan type. For education only — not legal advice. Last reviewed October 2026.
