Why Health Insurance Claims Get Denied, And What You Can Do About It

Mtech Growth,

Health insurance is supposed to protect you from overwhelming medical bills. Yet many Americans are surprised to receive a denial letter after a doctor visit, test, or procedure.

Understanding why claims are denied and how federal law like ERISA may apply can help you respond quickly and protect your rights.

How Often Are Health Insurance Claims Denied?

Health insurance claim denials are more common than most people think.

Industry studies and federal reports show that millions of claims are denied each year across employer-sponsored and individual plans. While denial rates vary by insurer and state, even a small percentage translates to thousands of families facing unexpected bills.

According to publicly available data compiled by the Centers for Medicare & Medicaid Services (CMS), consumers frequently file appeals challenging coverage determinations.

The key takeaway: A denial is frustrating but it is not necessarily the final word.

 

What Are the Most Common Reasons Health Insurance Claims Are Denied?

Most denials fall into predictable categories.

If you review common health insurance claim denial reasons, you’ll notice patterns tied to paperwork, policy language, and medical necessity standards.

Here are the most frequent issues:

1. Lack of Medical Necessity

The most cited reason for denial is that the treatment was “not medically necessary.”

Insurers define medical necessity based on internal guidelines. If a procedure, imaging study, or medication does not meet those criteria, the claim may be denied.

For example:

  • An MRI ordered for back pain may be denied without prior conservative treatment.
  • A brand-name medication may be denied if a generic alternative exists.

 

2. Out-of-Network Providers

Out-of-network services often trigger denials or reduced coverage.

Even when patients try to stay in-network, situations like emergency care can lead to surprise billing issues. Federal protections now address some of these concerns under the No Surprises Act, which is explained by the U.S. Department of Health and Human Services (HHS).

Still, network rules remain a major source of confusion.

 

3. Prior Authorization Failures

Some services require approval before treatment.

If prior authorization is not obtained even accidentally, insurers may refuse payment. This commonly affects:

  • Advanced imaging
  • Surgeries
  • Specialty medications

Administrative errors can cost patients thousands of dollars.

 

4. Coding and Billing Errors

Clerical mistakes can derail valid claims.

Incorrect CPT codes, mismatched diagnosis codes, or incomplete documentation often result in automatic denials.

In many cases, correcting the error leads to approval.

 

5. Policy Exclusions

Some treatments are explicitly excluded from coverage.

Examples may include:

  • Cosmetic procedures
  • Experimental therapies
  • Certain fertility treatments

Reviewing your policy’s Summary Plan Description (SPD) is critical to understanding coverage limits.

 

What Is ERISA and How Does It Affect Health Insurance?

ERISA governs most employer-sponsored health insurance plans.

The Employee Retirement Income Security Act of 1974 (ERISA) sets national standards for private employer benefit plans, including health insurance.

ERISA requires:

  • Clear claims procedures
  • Written explanations for denials
  • A formal internal appeal process
  • Specific deadlines for decisions

The law is enforced by the U.S. Department of Labor, which provides consumer guidance on benefit rights.

If you get insurance through your employer, ERISA likely controls your appeal rights.

 

Why ERISA Appeals Are So Important

Under ERISA, the internal appeal may be your most critical opportunity to present evidence.

Here’s why:

  • Courts often review only the administrative record.
  • You may not be allowed to introduce new evidence later.
  • Jury trials are typically unavailable.

This means your appeal should include:

  • Supporting medical records
  • Physician letters explaining medical necessity
  • Relevant clinical guidelines
  • Any documentation correcting errors

The U.S. Department of Labor Employee Benefits Security Administration (EBSA) outlines your right to receive denial explanations and file appeals within specified timeframes.

Deadlines are strict. Missing one can end your claim.

 

How Does the Affordable Care Act Protect Consumers?

The Affordable Care Act (ACA) expanded appeal rights.

Under federal law, non-grandfathered health plans must provide:

  • An internal appeal process
  • Access to an independent external review
  • Timely decision requirements

CMS provides consumer information about appeals and external review processes.

This means that even if your insurer upholds a denial internally, you may have the right to an independent review by a third party.

 

What Should You Do Immediately After a Denial?

The first step is to carefully read the denial letter.

The letter should explain:

  • The reason for denial
  • The policy provisions relied upon
  • Instructions for appeal
  • The deadline for response

Act quickly.

Create a checklist:

  1. Confirm the deadline.
  2. Request your full claim file.
  3. Speak with your healthcare provider.
  4. Gather supporting documentation.
  5. Submit a written appeal before the deadline.

Time matters.

 

A Real-World Example

Consider this situation:

A patient undergoes a medically recommended outpatient procedure. Weeks later, the insurer denies the claim, stating it was “not medically necessary.”

The patient requests the clinical criteria used for denial and asks her doctor to provide:

  • Peer-reviewed studies supporting the procedure
  • A detailed explanation of why conservative treatments failed
  • Documentation of worsening symptoms

On appeal, the insurer reverses the decision.

The denial was not about eligibility, it was about documentation.

 

How Federal Courts Review ERISA Health Claims

Federal courts typically apply a deferential standard in ERISA cases.

If the plan grants discretion to the insurer, courts often uphold denials unless they are “arbitrary and capricious.”

The United States Courts provides educational resources explaining how civil ERISA cases are handled in federal court.

Because of this standard, building a strong record during appeal is crucial.

 

How to Reduce the Risk of Future Denials

Proactive steps can prevent problems.

Before treatment:

  • Confirm coverage and network status.
  • Obtain prior authorization in writing.
  • Ask your provider to verify coding accuracy.
  • Keep copies of all communications.

After treatment:

  • Review Explanation of Benefits (EOB) statements carefully.
  • Address discrepancies immediately.

Being organized reduces stress later.

 

When to Seek Professional Guidance

Complex denials may require legal or professional assistance.

Situations where help may be useful include:

  • Large-dollar claims
  • Ongoing treatment disputes
  • ERISA appeals involving extensive medical evidence
  • Repeated denials despite corrections

An experienced professional can help interpret policy language and ensure deadlines are met.

 

Final Thoughts: Denials Are Common, But Often Reversible

A health insurance denial can feel overwhelming, especially when medical bills are already stressful.

But the system includes safeguards.

Between ERISA protections, ACA appeal rights, and federal oversight agencies, consumers have tools available to challenge decisions.

The most important step is simple: act quickly and stay organized.

Understanding common health insurance claim denial reasons, knowing your rights under federal law, and submitting a well-documented appeal can dramatically improve your chances of success.

Insurance policies are complex. But informed patients are empowered patients.

 

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