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Answer · Asking for the denial reason in writing

How to ask your insurer for the denial reason in writing

You are not alone, and you do not have to guess why they said no. Ask for the reason in writing, then ask for the file behind it.

CheckMyDenial team, patient billing and appeals. Published October 2026. Last reviewed 2026-10-29.

What do I say on the phone to get the denial reason in writing?

Keep it calm and short. You can say: "My claim was denied. Please send me the specific reason for the denial in writing, the criteria or guideline you used, and a copy of my claim file. Can you give me a reference number for this request?"

Write down the date, the time, the name of the person, and the reference number. If they say they cannot send it, ask them to note that you asked. Then send the same request as a letter so there is a record.

What exactly should I ask my insurer to send me?

Ask for three things: the specific reason your claim was denied, the criteria or guideline they relied on, and copies of the information in your claim file. You can also ask who reviewed it and what that person's credentials are. That last one is a fair question to ask, but treat it as a request, since they may not answer it.

If you think a coding mistake caused the denial, ask for the billing and diagnosis codes too. A CMS sample denial notice says you may request copies of information relevant to your claim free of charge, and that if a coding error may have caused the denial, you can have the billing and diagnosis codes sent to you.

Does my insurer have to explain why my claim was denied?

For many health plans, yes. HealthCare.gov says an insurer must notify you in writing and explain why. CMS says a denial notice must include the reason your claim was denied, your right to file an internal appeal, and your right to request an external review if the internal appeal does not succeed.

These federal appeal rights cover most private health plans, such as job-based plans and plans bought on your own. CMS says they do not apply to grandfathered plans, which are plans created or bought on or before March 23, 2010. Medicare and Medicaid have their own appeal rules. If your letter has no clear reason, ask for one anyway. Your plan, or your state insurance department, can tell you which rules apply to you.

How long do I have to appeal after a denial?

For plans that follow these federal rules, HealthCare.gov says you must file an internal appeal within 180 days (6 months) of getting notice that your claim was denied. Medicare, Medicaid, and grandfathered plans can have different deadlines, so always check the date in your own letter and go by that.

Do not wait for the written reason to arrive before you protect your deadline. Mark the date on your calendar the day you read the letter, and ask for the reason right away.

What happens after I ask and then appeal?

For plans that follow these federal rules, HealthCare.gov says the internal appeal must be finished within 30 days for a service you have not received yet, and 60 days for a service you already received. In urgent cases the decision must come as quickly as your medical condition requires, and no later than 4 business days after your request is received.

If the insurer still says no, you can ask for an external review. A reviewer outside the insurer decides, and HealthCare.gov says your insurer is required by law to accept that decision. HealthCare.gov says you must ask within 4 months after you receive the notice or final decision from your insurer. Medicare and Medicaid use their own review steps.

Step by step: how do I get the denial reason in writing?

Here is the simple order that works for most families.

  • Step 1: Find the date and the claim number. Look at your denial letter or explanation of benefits. Write down the date you got it, your member ID, and the claim number. Mark your appeal deadline on your calendar: the date your letter gives, or 180 days from when you got the notice if your plan follows the HealthCare.gov rule.
  • Step 2: Call and make the request. Call the member services number on your card. Say: "Please send me the specific reason for the denial, the criteria used, and a copy of my claim file." Write down the name, date, and reference number.
  • Step 3: Send the letter the same day. Use the template on this page. Send it by a method that gives you proof, such as the insurer's online portal message, certified mail, or fax with a confirmation page. Keep a copy.
  • Step 4: Follow up and keep everything in one folder. If nothing arrives in about two weeks, call again with your reference number. Keep every letter, note, and receipt together. If a deadline gets close, file your appeal anyway and add the documents when they come.

Can someone check my denial letter for me?

Yes. Text a photo of your denial letter to (213) 606-6303. We read it and reply with where it breaks. It is free, with no account and no form. We are not lawyers and this is not legal or medical advice, but we can help you see what to ask for next.

Your checklist

  • Write down the date you got your denial letter, your member ID, and the claim number.
  • Mark your appeal deadline on your calendar: the date in your letter, or 180 days if your plan follows the HealthCare.gov rule.
  • Call member services and ask for the reason, the criteria used, and your claim file.
  • Write down the name, date, time, and reference number of the call.
  • Send the request letter the same day, in a way that gives you proof.
  • Keep every letter and note in one folder.
  • Follow up in about two weeks if nothing arrives.

A letter you can copy

[Your full name] [Your address] [Phone and email] [Date] [Insurer name] Attn: Appeals / Member Services [Insurer address or fax] Re: Request for written denial reason and claim file Member name: [Name] Member ID: [ID] Claim number: [Number] Date of denial letter: [Date] Service and date: [What was denied and when] To whom it may concern, My claim listed above was denied. I am writing to ask for the following, in writing: 1. The specific reason my claim was denied. 2. The criteria, guideline, or rule used to make the decision. 3. A copy of the information in my claim file, including the billing and diagnosis codes. 4. The name and credentials of the person who reviewed my claim. I plan to appeal and want to protect my deadline. Please also send me the steps and the deadline to file an appeal. I spoke with [representative name] on [date], reference number [number]. Please reply to the address above by [date, about 14 days out]. Thank you for your help. Sincerely, [Your name]

Which rules apply to you?

The steps and deadlines on this page can differ by the kind of plan you have. Your own denial letter always comes first.

  • Coverage through a job:ask your HR team whether the plan is “self-funded” or “fully insured.” It can change who you can ask for help. Most private-sector job plans fall under a federal law called ERISA, and the U.S. Department of Labor’s EBSA takes health plan questions at Ask EBSA or 1-866-444-3272.
  • Marketplace plan: follow the appeal steps at HealthCare.gov.
  • Medicare or Medicaid: each has its own appeal process, listed on your notice.
  • Dental-only plan: your plan contract sets the appeal rights, so read it and your letter.

Related answers

Sources: HealthCare.gov: Internal appeals. HealthCare.gov: External review. CMS: Appealing health plan decisions. CMS: Model notice of adverse benefit determination. More in the full appeal guide.

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Free tools for the next step

Keep your appeal papers in one place. Take a photo of your denial letter, EOBs and insurance cards with GetPreCare, so they are on your phone when the insurer or the office asks. Free. Open GetPreCare. Helping a parent or partner? Set it up for them.