Quick Takeaway
Opening an Explanation of Benefits and seeing:
CLAIM DENIED
can be alarming—especially when the medical bill involves hundreds or thousands of dollars.
But a denial doesn’t automatically mean:
You have to pay the entire bill.
Some claims are denied because of administrative errors. Others involve prior authorization, network rules, medical-necessity decisions or exclusions under the plan.
And importantly, many consumers have formal appeal rights.
CMS states that when a health insurance plan denies payment for a medical service, consumers can generally request an internal appeal asking the insurer to reconsider. Depending on the plan and type of denial, an unsuccessful internal appeal may then qualify for an independent external review.
The key is to determine:
Why was the claim denied?
Once you understand that, you can decide whether the problem requires:
A corrected claim
Additional documentation
A doctor’s medical-necessity letter
An internal appeal
or:
An independent external review.
First: A Denied Claim Is Not Always a Final Bill
One of the biggest mistakes patients make is receiving an Explanation of Benefits—EOB—and assuming:
“My insurance denied it, so I owe this amount immediately.”
An EOB isn’t necessarily the same thing as a provider’s bill.
It explains how the insurer processed the claim.
Before paying a large disputed amount, compare:
Your EOB
with:
The healthcare provider’s actual bill.
CMS specifically recommends contacting the provider when the EOB doesn’t match the bill because billing errors can occur.
The 5 Common Reasons Health Insurance Claims Are Denied
1. Incorrect or Missing Information
Sometimes the problem isn’t your healthcare.
It’s:
paperwork.
A claim can encounter problems because information was entered incorrectly or incompletely.
Potential issues include:
Incorrect patient information
Incorrect insurance information
Missing documentation
Coding problems
Duplicate claims
or:
Incorrect service details.
These situations may be easier to resolve than a genuine coverage dispute.
Example: A Simple Coding Problem
Imagine you receive a covered medical procedure.
Your provider submits the claim.
The insurer denies it.
After contacting the billing department, you discover that the claim contained an incorrect billing code.
The provider corrects the information and resubmits it.
That’s very different from an insurer saying:
“This procedure isn’t covered by your policy.”
So your first response to a denial shouldn’t automatically be:
File a lengthy appeal.
First determine whether the claim simply needs correcting.
What to Do
Contact the provider’s billing department and your insurer.
Ask:
“What exact denial code and reason were used?”
Then ask whether the claim can be:
corrected and resubmitted.
Keep records of:
Who you spoke with
Date and time
Reference number
and:
What they told you.
HealthCare.gov specifically recommends documenting the date, time, name and title of people you speak with during the appeals process.
2. Prior Authorization Was Missing
Health plans may require:
Prior authorization
before certain services, treatments, procedures or medications.
That means the insurer wants to evaluate the requested care before it occurs.
Depending on your plan, prior authorization requirements might apply to:
Advanced imaging
Certain surgeries
Specialty medications
Some therapies
Medical equipment
and other services.
If the required authorization wasn’t obtained, the insurer may deny or limit payment.
“My Doctor Ordered It” Doesn’t Necessarily Mean “Insurance Approved It”
This distinction is critical.
Your physician might say:
“You need an MRI.”
That’s a medical recommendation.
Your insurance policy might separately require:
prior authorization.
Those are different processes.
Never assume your doctor’s recommendation automatically means your insurance company has authorized payment.
What to Do
Ask your insurer:
Was prior authorization required?
Was authorization requested?
Was it approved, denied or never submitted?
Then ask your provider’s office:
“Do you have an authorization number?”
If authorization was required but missing, ask whether the provider can submit additional documentation or whether a retrospective review is available under your plan.
The exact options depend on the policy and circumstances.
3. The Insurer Says the Treatment Wasn’t Medically Necessary
This is where denials become more complicated.
Your physician recommends treatment.
But your insurer determines that the service doesn’t satisfy its applicable:
medical-necessity criteria.
HealthCare.gov specifically lists a determination that a requested service or treatment is “not medically necessary” as a type of denial that may be appealed.
This is often where your doctor’s involvement becomes especially valuable.
Example: Physical Therapy
Suppose your doctor recommends:
20 physical-therapy sessions.
Your insurer authorizes:
10.
The plan determines that additional sessions don’t satisfy its medical-necessity requirements.
Your therapist believes stopping treatment would interfere with your recovery.
This isn’t necessarily the end.
Your appeal could include evidence showing:
Your diagnosis
Functional limitations
Treatment progress
Why additional therapy is necessary
and:
What could happen if treatment stops.
Ask Your Doctor for a Medical-Necessity Letter
A strong supporting letter may explain:
Your diagnosis
Your symptoms
Previous treatments attempted
Why those treatments failed or were inadequate
Why the requested treatment is appropriate
What could happen without treatment
and:
Relevant clinical evidence.
CMS confirms that consumers can submit additional information during an internal appeal, including a letter from their doctor.
4. You Used an Out-of-Network Provider
Many health plans use:
provider networks.
An insurer negotiates rates with participating:
Doctors
Hospitals
Laboratories
Imaging centers
and other healthcare providers.
Depending on your plan type, receiving non-emergency care outside that network can result in:
Higher costs
or potentially:
No coverage.
HealthCare.gov identifies out-of-network care as one reason a health plan may deny a claim.
But Out-of-Network Doesn’t Always End the Discussion
Suppose you deliberately scheduled a non-emergency appointment with a doctor who wasn’t in your network.
Your appeal options may be limited by your plan terms.
But now consider another situation.
You visit:
an in-network hospital.
You reasonably believe your treatment will be in network.
An out-of-network provider becomes involved in your care.
That situation can potentially implicate federal protections under the:
No Surprises Act
depending on the circumstances.
So don’t automatically accept a massive out-of-network bill without investigating why the provider was out of network and which protections apply.
Network Directories Can Also Create Problems
Suppose your insurer’s directory indicated that a physician was:
In Network.
You scheduled treatment based on that information.
Later, the claim is processed as:
Out of Network.
Document everything.
Save:
Screenshots
Provider-directory information
Emails
Reference numbers
and:
Call records.
Evidence that you reasonably relied on information supplied by the plan can be important when disputing the result.
5. The Service Isn’t Covered by Your Plan
This is one of the hardest denials to overturn.
Health insurance doesn’t cover:
every healthcare service.
A plan can exclude certain treatments or services.
HealthCare.gov identifies denials involving a benefit that isn’t offered under the health plan as appealable through the internal appeal process.
However, an appeal is more difficult if the policy clearly excludes the benefit and the exclusion legally applies.
Experimental or Investigational Treatment
Another related denial involves treatments classified by the insurer as:
Experimental
or:
Investigational.
This doesn’t necessarily mean the treatment is unsafe.
It means the insurer determined it doesn’t meet the plan’s applicable coverage criteria.
HealthCare.gov says denials involving experimental or investigational treatment can be appealed and may qualify for external review.
Read the Exact Denial Reason
Don’t appeal by simply writing:
“This is unfair. Please pay my bill.”
Your appeal should directly address:
the insurer’s reason for denying the claim.
Look for wording such as:
Not medically necessary
Prior authorization required
Out-of-network provider
Benefit excluded
Experimental/investigational
or:
Insufficient information.
The denial notice should explain why the claim was denied and provide information about your appeal rights.
Step 1: Read Your Explanation of Benefits
Start with the:
Explanation of Benefits (EOB).
Look for:
Claim number
Date of service
Provider
Amount billed
Allowed amount
Amount insurer paid
Amount you’re responsible for
and:
Denial reason/code.
Keep the EOB.
You’ll likely need it if the dispute escalates.
Step 2: Call the Insurance Company
Call the member-services number on your insurance card.
Ask:
“Please explain exactly why this claim was denied.”
Then ask:
What provision of my plan was used?
Can you give me the denial code?
Can the provider correct and resubmit the claim?
What documentation is missing?
Do I need to file a formal appeal?
What’s my deadline?
Write down the answers.
Step 3: Call Your Provider
Now contact the:
billing department.
Tell them the insurer denied the claim.
Ask whether they see:
Coding errors
Missing documentation
Incorrect patient information
Authorization problems
or:
Submission errors.
If it’s an administrative error, the provider may be able to fix the claim without requiring a full appeal.
Step 4: Get Your Medical Records
If the denial involves medical necessity, gather evidence.
That may include:
Medical records
Diagnostic test results
Imaging reports
Treatment history
Medication history
Specialist recommendations
and:
Physician letters.
The goal is to demonstrate why the treatment satisfies your plan’s coverage requirements.
Step 5: Read Your Plan Documents
Look at your:
Summary of Benefits and Coverage
and, when necessary:
full policy or Summary Plan Description.
Search for the benefit involved.
For example:
Physical therapy.
Determine:
Is it covered?
Is prior authorization required?
Is there an annual visit limit?
Does the deductible apply?
Are there network restrictions?
Your appeal becomes stronger when you can point to the actual policy language.
Step 6: File the Internal Appeal
An internal appeal asks the insurance company to:
reconsider its own decision.
CMS explains that consumers can generally appeal a denial and require the plan to review its decision.
HealthCare.gov says an internal appeal can include:
The insurer’s required forms
or a written request containing:
Your name
Claim number
and:
Health insurance identification number.
You can also submit supporting information such as your doctor’s letter.
What Your Appeal Letter Should Include
Keep it organized.
Include:
Patient information
Name and insurance information.
Claim information
Claim number and date of service.
Treatment
What service or medication was denied.
Denial reason
Quote or accurately summarize the insurer’s explanation.
Why you disagree
Explain specifically why you believe the service should be covered.
Supporting evidence
Include relevant:
Medical records
Physician letters
Plan language
Prior authorization
and other documents.
Requested outcome
Clearly state:
“I request that the denial be reversed and the claim reprocessed according to my plan benefits.”
A Simple Appeal Structure
Your argument might look like this:
Claim: 123456
Service: MRI
Denial: Medical necessity
Reason for appeal: My treating physician determined the MRI was necessary after conservative treatment failed.
Evidence included: Physician letter, treatment notes and prior test results.
Requested resolution: Reverse the denial and process the claim as a covered benefit under my plan.
Clear beats emotional.
Watch Your Deadline
Deadlines matter.
Under the federal process described by HealthCare.gov and CMS, consumers generally have 180 days after receiving a denial notice to file an internal appeal for plans subject to those requirements.
But you should follow:
the deadline stated in your denial notice and plan documents.
Don’t wait until the last week.
How Long Can an Internal Appeal Take?
For plans subject to the federal ACA appeals requirements, CMS says decisions generally must be provided within:
72 hours
for urgent-care appeals,
30 days
for denials involving non-urgent care you haven’t yet received,
and:
60 days
for services you’ve already received.
Different rules can apply depending on the plan and circumstances.
What If Your Health Is at Risk?
Don’t assume every appeal has to move slowly.
If waiting through the normal process could seriously jeopardize your:
Life
Health
or:
Ability to regain maximum function,
an expedited appeal may be available.
CMS says urgent appeals may receive expedited handling, and in qualifying urgent situations an external review may sometimes proceed at the same time as the internal appeal.
What If Your Internal Appeal Is Denied?
You may still have another option:
External Review.
This is important because the decision is no longer being reviewed only by the insurer.
An independent third party evaluates the eligible dispute.
CMS explains that an external reviewer can either:
uphold the denial
or:
overturn it.
When an applicable external reviewer overturns the denial, the insurer must accept that decision.
What Types of Cases Can Go to External Review?
HealthCare.gov identifies examples including denials involving:
Medical judgment
Medical necessity
Experimental or investigational treatment
and certain:
Coverage rescissions.
Eligibility depends on the plan and applicable state or federal process.
Your final internal denial notice should explain your next steps.
Important: Check the External Review Deadline
HealthCare.gov currently says that under its described process, a written external-review request generally must be filed within:
four months
after receiving the applicable denial or final determination.
Because procedures can vary, always use the deadline stated in your own notice.
Employer Health Plans Can Be Different
If your insurance comes through work, determine whether the plan is:
Fully insured
or:
Self-funded.
CMS specifically recommends asking your HR department this question when dealing with a denied employer-plan claim.
Why?
Because different regulatory and appeals structures can apply.
Some employer-sponsored plans may also require more than one level of internal appeal before an external review becomes available.
Don’t Ignore Your HR Department
If your employer provides the coverage, HR or your benefits administrator may help you understand:
Plan rules
Appeal procedures
Plan documents
and:
Who administers the claim.
For a self-funded employer plan, the insurance company’s logo on your card may represent the company administering claims rather than the entity ultimately bearing the insurance risk.
That distinction can matter during disputes.
Keep an Appeal File
Create one folder containing:
EOB
Provider bills
Denial letters
Insurance policy
Summary of Benefits
Medical records
Doctor’s letter
Prior authorization
Appeal forms
Emails
Fax confirmations
Certified-mail receipts
and:
Call notes.
Don’t rely on memory.
Keep Originals
HealthCare.gov recommends keeping your original documents and submitting copies when appropriate.
Also record:
Date
Time
Representative’s name
Department
Reference number
What was discussed
after every important phone call.
If someone promises:
“We’ll reprocess the claim,”
ask for a reference number.
Don’t Ignore the Provider’s Bill During an Appeal
While disputing a claim, contact the healthcare provider’s billing department.
Tell them:
the insurance claim is under active appeal.
Ask what options are available while the dispute is pending.
Depending on the provider, they may have:
Payment arrangements
Financial-assistance programs
or procedures for:
Pending insurance appeals.
Don’t simply ignore bills, because that can create additional problems.
What If the Denial Is Correct?
Sometimes the insurer’s decision accurately reflects the policy.
For example, suppose your plan clearly excludes a particular elective service.
If the exclusion legally applies and there isn’t another coverage basis, an appeal may not change the outcome.
You can still verify that the claim was processed correctly.
But insurance appeals aren’t a mechanism for creating coverage that the contract genuinely doesn’t provide.
Five Mistakes That Can Hurt Your Appeal
1. Missing the deadline
Even a strong argument can fail procedurally if filed too late.
2. Sending an emotional letter without evidence
Focus on the plan language and medical facts.
3. Not involving your doctor
For medical-necessity disputes, clinical evidence can be critical.
4. Not identifying the exact denial reason
You can’t effectively challenge an argument you haven’t identified.
5. Giving up after the first denial
An internal denial may not necessarily be the final available level of review.
Health Insurance Claim Appeal Checklist
When a claim is denied:
- Read the denial notice and EOB.
- Identify the exact denial reason.
- Write down the claim number.
- Compare the EOB with the provider’s bill.
- Call the insurer.
- Ask for the denial code.
- Ask which policy provision was used.
- Call the provider’s billing office.
- Check for coding or administrative errors.
- Verify prior authorization.
- Verify network status.
- Read your plan documents.
- Collect relevant medical records.
- Ask your physician for supporting documentation when appropriate.
- Determine the appeal deadline.
- File your internal appeal on time.
- Keep copies of everything.
- Record all calls and reference numbers.
- Ask about expedited review when medically urgent.
- Review external-review rights if the internal appeal fails.
- Contact HR for employer-sponsored coverage when appropriate.
- Keep the provider informed while the appeal is pending.
Frequently Asked Questions
Why was my health insurance claim denied?
Common reasons include administrative or coding problems, missing prior authorization, medical-necessity determinations, out-of-network treatment and services the plan says aren’t covered. HealthCare.gov confirms that medical necessity, network status, excluded benefits and experimental treatment are among the types of denials consumers may appeal.
Can I appeal an insurance claim denial?
Yes. Consumers covered by applicable health plans generally have the right to request an internal appeal. Some unresolved denials can then qualify for independent external review.
How long do I have to file an internal appeal?
Under the federal process described by CMS, consumers generally have up to 180 days after receiving the denial notice to request an internal appeal. Check your own denial notice for the applicable deadline.
Can my doctor help appeal?
Yes. HealthCare.gov specifically identifies a doctor’s letter as additional information that can be submitted with an internal appeal.
What happens if my appeal is denied?
Depending on your plan and type of denial, you may qualify for an independent external review. The denial notice should explain your external-review rights and procedures.
Does an external reviewer work for my insurer?
The purpose of external review is to have an independent decision-maker outside the health plan review an eligible denial.
Does the insurer have to follow the external review decision?
For applicable external reviews, yes. HealthCare.gov says the insurer is required to accept the external reviewer’s decision.
Final Thoughts
A denied health insurance claim can look final.
Often, it isn’t.
The most important thing you can do is determine:
exactly why the insurer denied the claim.
If it’s an administrative mistake, the provider may simply need to correct and resubmit it.
If it’s a prior-authorization issue, additional documentation may help.
If the insurer disputes medical necessity, your physician’s records and supporting explanation can become central to your appeal.
If it’s a network dispute, investigate exactly how and why the out-of-network provider became involved.
And if the insurer maintains its denial after internal review, you may have access to:
independent external review.
Federal consumer protections give many insured Americans meaningful rights to challenge health-plan decisions rather than simply accepting the first “no.”
So when an EOB says:
DENIED
don’t immediately translate that into:
I have to pay.
Translate it into:
Why was it denied, what does my policy say, and what evidence do I need to challenge the decision?
That is where an effective appeal starts.