Did your insurance deny your health care claim? How to appeal.

Follow these simple steps to challenge a health care claim denial. It's worth it.

Whether you have Medicare or private insurance, learn how to challenge health insurance claim denials with this easy guide.

You can appeal health insurance claim denials. Follow these simple steps.

It’s a terrible feeling. You open a letter from your health insurance to see coverage for some of your recent care was denied. Now you have to deal with a medical bill that is far bigger than you were expecting.

When you go to the doctor or get lab work, scans or images, your insurance provider should cover most of that cost, depending on your plan. However sometimes, insurance companies deny claims, which means you need to pay for it yourself. Claim denials are happening more often with the use of technology that limits individual claim reviews by doctors employed by insurers. In 2020, almost 1 in 5 insurance claims were denied. Even though patients have the right to challenge those denials, less than one percent do. But insurance companies do make mistakes. That’s why it makes sense to challenge health insurance claim denials.

Some reasons for incorrect denials:

  1. Your insurance plan wrongly decided the service is no longer medically necessary for your care.
  2. Your insurance wrongly denied a claim for a service that should be included in your coverage.
  3. Your doctor or hospital incorrectly filed the claim. (Provider wrote the wrong billing code, didn’t provide all the information the plan needed or other errors, etc.)

Depending on your plan, insurance can pay the entire cost of your healthcare service or you may need to pay for a portion of the claim: the copay, coinsurance and deductible. Preventable services are usually fully covered.

If you think your insurance should not have denied your claim: 

It’s worth it to challenge claim denials. By following these steps, you could get a claim denial reversed and your insurance could end up covering most, or all, of the bill.

First, review your bill. If something seems wrong: 

  1. Contact your healthcare provider. Make sure that they have billed you for the correct amount, and that the bill was not an error.
  2. Contact your insurer. Use the number on the back of your insurance card. Explain why you think there is an error and why you believe the claim should not have been denied.

If this doesn’t work, you can file a formal appeal. The processes for formal appeals are different for Medicare plans than for other types of insurance. We explain both types of appeals below.

Challenging health insurance claim denials.

When challenging a claim denial, keep a copy of your records. Here's what to keep.

When challenging a claim denial, keep a copy of your records:

  • Your Explanation of Benefits (EOB) form details which costs are covered by insurance and which are denied. (Only those with private insurance have EOB’s)
  • For Medicare beneficiaries, your Medicare Summary Notice (MSN) form details which costs are covered by Medicare and which are denied. 
  • Your letter requesting an appeal. 
  • Letters or forms you have to sign for your doctor or insurance which relate to the appealed claim. 
  • Notes on any conversations you have with your insurer. Get the name of the person, and write down the time, date and phone number.

Keep the original of your documents and only submit copies for your appeals.

Challenging Medicare health claim denials

For those insured through Medicare:

Step 1: Find your Medicare Summary Notice (MSN). An MSN is sent every 3 months from your insurer. Or look it up on your online Medicare portal.

Step 2: Check the date of the MSN. You have 120 days after receiving your MSN to file your appeal. If you missed that deadline, when you file your appeal be sure to explain why you are late. You can login to see your claims at any time on your online Medicare portal

Step 3: Look at the MSN to see which claims were denied. This is considered the “initial determination.” Make a copy of the MSN and circle the denied claims that you want to appeal. 

Step 4: Fill out a Redetermination Request Form. If you can’t print out this form, you can write a letter that includes all of this information. Try to include as much information as possible but don’t worry if you don’t have all of the information. 

Step 5: Find the address for your insurer listed on your MSN and mail the Form or your letter. 

You should know within 60 days of sending in this appeal. If your appeal to the insurance company is unsuccessful, you have 4 other levels of appeal.  The next steps can be found here.

Challenging health claim denials, if you have private insurance

For those with private insurance: 


Start with an “internal appeal.” The insurance company will review decision to deny your claim based on the information you submit. Here’s how:


Steps to file an internal appeal:


Step 1: Find your Explanation of Benefits (EOB), which details the claims and the amounts you owe. It might come by mail, or you can access it through your online account with your insurance company. 

  • Identify any denied claims on your EOB that you want to appeal. 
  • Check the date of the EOB. You must appeal within 6 months of the claim denial.


Step 2: Write a letter to your insurer explaining which claim you would like to appeal and why. Here is an example letter. Be sure to include your name, address, phone number, plan number, and which denied claims you are appealing. Include a copy of the EOB. 


Step 3: If you want, you can also include other information which you believe supports your appeal. You might want to include a letter from your doctor explaining why you needed the treatment. Or send copies of the parts of your medical record that show why you need the treatment or service. Here’s how to get a free copy of your medical record.


You should know whether you won your appeal within 30 days of sending it in. If your internal appeal is unsuccessful, you can request an external appeal.


How to file for an external appeal for a denied health claim


If you don’t win the internal appeal, you can file an external appeal. In external appeals, a third party is the final authority, not the insurance company.

Your Explanation of Benefits will have the contact information for the organization that will handle your external review. You must file an appeal for external review within 4 months of your denied internal appeal (or explain your reasoning for your inability to file on time). Note that you will have to pay $25 for your external review, and the decision from the external reviewer is final.

Words you should know (a list of definitions)

Claim: A request for payment that you or your health care provider sends your health insurer when you get health care items or services 

MSN: Medicare Summary Notice, document with all your claims, and their payment status, for the last 3 months

Redetermination request form: the form you fill out to officially ask for the denial to be reconsidered

Explanation of Benefits (EOB): A document from your insurer that explains what treatment and services are covered and what claims are denied. It also contains the information on how to file for an appeal of any denied claims. 

Coinsurance: An amount you must pay out-of-pocket as a percentage of the price of the service. It is in the form of a percentage (such as, 10%). For example, if the cost of a service is $600 and you have 10% coinsurance, you are responsible for paying $60 as your coinsurance.

Copay: A fixed cost you must pay out-of-pocket for a specific service, like a prescription drug or a primary care appointment. For example, you may have to pay $20 for every doctor visit, or $20 for a certain type of medication every time you refill that prescription. you will pay $20.

Deductible: The amount of money you must pay out-of-pocket at the beginning of your insurance plan year. Check with your insurance company to understand when your insurance plan year starts and ends. After reaching the deductible, you will typically pay less for services. 

For example, at the beginning of the plan year, if your first medical bill is $6000, and you have a $2,000 deductible, you will owe $2,000 and insurance will cover the remaining $4,000. Or if your first medical bill is $500, you will pay the full $500 for that service. And you will continue to pay all of the cost of any future care until you have paid $,2000 (your deductible amount). Your insurance will then take over paying the bills. Remember, you will also have to pay any copay or coinsurance.

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