For many private health plans, federal rules give you at least 180 days from the denial notice to file an internal appeal. Marketplace and employer-sponsored plans can have different procedures, and Medicare or Medicaid can follow different timelines, so use your own plan documents first. This guide is general information, not legal advice.
Start With the EOB and Denial Notice
An EOB is not just a payment summary. It usually shows the service date, provider, billed amount, what the insurer paid, what you may owe, and the reason code or remark tied to the denial. Pair it with the denial letter and look for these details before you write anything:
- The exact service, treatment, or claim that was denied
- The stated reason, such as out-of-network care, missing prior authorization, lack of medical necessity, or plan exclusion
- The plan provision or benefit rule the insurer relied on
- The deadline, address, fax number, portal, or form required for the appeal
- Whether the claim is pre-service, post-service, or urgent
If anything is unclear, request the records the plan used to make its decision. Federal guidance for many employer plans says you can ask for relevant claim documents and other information free of charge.
Internal Appeal Timelines at a Glance
These are common federal timeframes for Marketplace and many employer health plans. Your plan may provide more generous rights, and some employer plans can require two internal appeal levels before external review.
| Claim type | What it means | Typical appeal review timeline |
|---|---|---|
| Pre-service | You have not received the treatment yet, often a prior authorization denial | Usually no more than 30 days after the appeal is received |
| Post-service | You already received the care and payment was denied | Usually no more than 60 days after the appeal is received |
| Urgent care | Waiting could seriously jeopardize your health or recovery | Expedited review, often within 72 hours |
How to Appeal Step by Step
1. Mark the internal review deadline immediately
Put the deadline on your calendar the day you receive the denial. If the notice gives a mailing address, portal, or fax number, note that too. If the deadline is close, prepare a short but complete appeal now rather than waiting for a perfect packet.
2. Match your evidence to the denial reason
Use the EOB and denial letter to identify what the insurer is challenging. If the denial says no prior authorization, address authorization history. If it says not medically necessary, focus your appeal on clinical facts, diagnosis, failed treatments, and why the service meets the standard of care.
3. Gather the core appeal packet
At minimum, keep copies of the EOB, denial notice, your appeal letter, and any records you send. Also save phone notes with dates, names, and reference numbers. Healthcare.gov specifically advises keeping copies of everything related to the claim and denial.
4. Get a targeted doctor’s letter
A doctor’s letter can be the strongest part of the file if it is specific. Ask your physician to write a brief letter on letterhead that identifies your diagnosis, the requested treatment or service, why it is medically necessary, and what could happen if care is delayed or denied.
A practical tactic, inferred from federal guidance telling you to use the denial notice and submit additional evidence, is to have the doctor answer the insurer’s reason for denial point by point. A strong letter often includes failed prior treatments, relevant test results, the expected benefit of the requested care, and why alternatives are not appropriate in your case.
5. Write a focused appeal letter
Your appeal letter does not need legal language. It needs precision. Include your name, member ID, claim number, date of service, provider, and a clear statement that you are appealing the denial. Then explain why the denial should be overturned, referring to the EOB, the denial reason, and the attached doctor’s letter.
Keep the body organized in short sections:
6. Submit before the deadline and prove delivery
Send the appeal exactly the way the notice requires. If the plan allows mail, use a trackable method. If it allows fax, keep the confirmation page. If it allows portal upload, save screenshots and submission receipts. Keep originals unless the plan specifically requires an original signature.
7. Track the review and be ready for the next level
After submission, confirm the appeal was received and ask when a decision is due. Under federal rules for many plans, the appeal must be reviewed by someone new, not the original decision-maker. If the plan still denies the claim, the final internal denial should explain how to request an external review.
What the Doctor’s Letter Should Cover
If your doctor agrees to help, ask for a letter that is short, factual, and tied to the denial. The most useful letters usually cover:
- Your diagnosis and relevant medical history
- The exact service, drug, test, or treatment requested
- Why it is medically necessary for your condition
- What treatments were tried already and why they were not enough
- What harm, delay, or added cost may result if the denial stands
That kind of detail gives the insurer something concrete to review instead of a general request for sympathy.
Common Mistakes That Weaken Appeals
- Missing the filing deadline
- Sending only a complaint without addressing the denial reason
- Forgetting to include the claim number, member ID, or service date
- Submitting records without a clear cover letter tying them to the denial
- Failing to keep proof of submission
Where to Get Official Help
Use official guidance if you want to double-check your rights. The clearest starting points are Healthcare.gov’s internal appeals page, the U.S. Department of Labor guide for health benefit claims, and the CMS fact sheet on internal and external appeals. If you need help filing, ask whether your state has a Consumer Assistance Program. If the internal appeal fails, review external review rules right away because that deadline can be shorter.
FAQ
Is an EOB the same as a denial letter?
No. An EOB explains how the claim was processed and what was paid or not paid. The denial letter usually gives the insurer’s formal reason and your appeal rights. Keep both because they support each other.
What if the internal review deadline is only a few days away?
File the appeal before the deadline using the required method, even if you are still gathering extra records. State that you are appealing the denial, identify the claim, attach the EOB and any available doctor’s support, and keep proof that it was sent. Then ask the plan whether it will accept additional records after filing.
What happens if my internal appeal is denied?
You should receive a written decision explaining the outcome and the next step. Many plans then allow an external review by an independent reviewer, and some employer-sponsored plans may require a second internal appeal first. Follow the instructions in the final denial notice immediately because external review deadlines can be short.