Which Health Insurance Companies Deny the Most Claims? What Consumers Really Need to Know

When people search for “which health insurance company denies the most claims,” they’re usually trying to answer a deeper question:

That’s the right question to be asking. But there’s a problem: there’s no single, clear, public ranking that reliably shows which specific company denies the most claims across all plans, states, and situations.

Instead, there are patterns and red flags that can help you understand:

• Why claims get denied
• Which types of plans and companies may be more likely to deny
• How to compare insurers more smartly
• What you can do to protect yourself and appeal a denial

This guide breaks that down in plain language.

Why You Won’t Find a Simple “Worst Company” List

It’s tempting to look for a list that names and shames the health insurance company that denies the most claims. In reality, that kind of list is usually:

• Misleading – Different data sources look at different types of plans
• Incomplete – Not all companies or plans are included
• Not apples-to-apples – One company may process millions more claims than another

Claim denial rates vary widely by:

• Type of plan

  • Employer group plans
  • Marketplace (ACA/exchange) plans
  • Medicare Advantage
  • Medicaid managed care

• State and region
  Rules and enforcement differ from place to place.

• Network design
  Narrow networks or strict preauthorization rules can affect denials.

Because of this, experts usually focus less on which insurer denies the most claims overall and more on how transparent, responsive, and appeal-friendly a particular insurer or plan is.

What “Claim Denial” Really Means

Before judging any company, it helps to understand what a claim denial actually is.

A claim denial happens when your insurer decides not to pay all or part of a bill submitted by you or your provider. That doesn’t always mean the insurer acted unfairly.

Common reasons health insurance claims are denied

1. Administrative or technical errors

   • Incorrect patient info
   • Wrong billing codes
   • Missing documentation
     These can often be fixed and resubmitted.

2. Out-of-network care

   • You saw a provider or went to a facility outside your plan’s network
   • Emergency situations may be treated differently, but balance bills can still happen in some scenarios

3. Lack of preauthorization

   • Certain tests, procedures, or medications require prior approval
   • If that approval wasn’t obtained, the claim may be denied

4. Coverage exclusions and limits

   • The service isn’t covered under your policy
   • You hit a visit limit or benefit cap in your plan

5. Medical necessity disputes

   • The insurer decides a service was not medically necessary under its internal criteria

6. Eligibility issues

   • Coverage lapsed, premiums unpaid, or the date of service was before coverage started

Some of these are preventable with planning, while others can be challenged through an appeal.

Types of Insurers and Where Denials Often Show Up

While it’s risky to label a single company as “the worst,” consumers and professionals do notice trends across types of plans and programs.

1. Large national commercial insurers

Big-name private insurers handle huge volumes of claims each year. That means even a small percentage of denials can affect many people.

Patterns often reported by consumers include:

• Strict preauthorization requirements
• Narrow provider networks
• Close scrutiny of imaging, specialty drugs, and some elective procedures

Some plans from large insurers may feel tighter or more restrictive; others may be more generous. It often depends on:

• The specific plan design your employer or you selected
• Whether it’s a HMO, EPO, PPO, or POS
• Whether your plan is self-funded by an employer (where the employer, not the insurer, bears the claims cost)

2. Marketplace (ACA/exchange) plans

On Health Insurance Marketplace or “Obamacare” plans, denial rates can vary by:

• State
• Insurer
• Metal tier (Bronze, Silver, Gold, Platinum)

Consumers sometimes report:

• More network-related denials due to narrower networks
• Higher scrutiny of out-of-network claims
• Occasional administrative challenges in the early months of coverage

On the upside, these plans have defined essential health benefits and formal appeal rights, which can help if a claim is wrongly denied.

3. Medicare Advantage plans

Medicare Advantage plans are run by private insurers under Medicare rules. Consumers and clinicians commonly describe:

• Frequent requests for prior authorization, especially for:
  • Skilled nursing
  • Home health
  • Certain tests and imaging
• Disagreements over whether extended care is medically necessary

At the same time, many enrollees are satisfied with extras like limited dental or vision coverage and caps on out-of-pocket costs.

Here again, denial rates and experiences can differ widely between insurers and between plans from the same insurer.

4. Medicaid managed care plans

In many states, Medicaid is administered by private managed care organizations. Denials may be driven by:

• Network restrictions
• Strict documentation and prior authorization requirements
• Challenges with administrative processing

Lower-income enrollees may face extra barriers in appealing denials or switching plans, even when they have those rights.

How to Think About “Which Company Denies the Most Claims”

Instead of asking only, “Which health insurance company denies the most claims?”, it’s more useful to ask:

• How often does this plan deny claims compared with other options locally?
• What kinds of claims are most likely to be denied?
• How easy is it to get answers, help, and appeals?

Because people use different doctors, hospitals, and services, two customers on the same insurance company can have very different denial experiences.

Red Flags and Green Flags When Evaluating an Insurer

Here’s a practical way to compare plans and companies—not by marketing, but by behavior.

Red flags (potential denial trouble spots)

• Very narrow networks where your key doctors/hospitals are out-of-network
• A history of slow customer service or difficulty reaching a live representative
• Frequent reports of surprise denials for care that seemed routine
• A reputation for aggressive preauthorization of basic imaging or medications
• Confusing or hard-to-obtain plan documents

Green flags (more consumer-friendly signs)

• Clear, accessible Summary of Benefits and Coverage (SBC)
• Straightforward appeal instructions written in plain language
• Responsive customer service with multiple contact options
• Network that includes your existing providers and preferred hospital system
• Transparent rules for referrals and preauthorizations

Key Factors That Influence Claim Denial Rates

It’s not just “who” your insurer is. These factors also matter:

1. Plan type: HMO vs PPO vs EPO vs POS

• HMO (Health Maintenance Organization)

  • Requires a primary care provider (PCP) and referrals
  • Generally no coverage for out-of-network care (except emergencies)
  • Denials frequently tied to referral and network rules

• PPO (Preferred Provider Organization)

  • More flexibility to see specialists without referrals
  • Some out-of-network coverage, but at a higher cost
  • Denials more likely over out-of-network costs and medical necessity

• EPO (Exclusive Provider Organization)

  • Like a mix of HMO and PPO: no out-of-network coverage except emergencies
  • Fewer referrals than a strict HMO, but tight network rules

• POS (Point of Service)

  • Requires referrals but allows out-of-network use at a higher cost
  • Denials often linked to improper referrals or out-of-network claims

2. Network design

Plans with narrow networks may have:

• Lower premiums
• Higher risk of out-of-network denials if you’re not careful

Plans with broad networks may reduce denial risk for network reasons but still deny for:

• Lack of preauthorization
• Medical necessity disputes
• Policy exclusions

3. Level of utilization review

Some companies and plans rely heavily on:

• Prior authorization
• Step therapy (trying lower-cost options first)
• Concurrent review during a hospital stay

This can mean more initial denials, but many are later overturned on appeal or resubmission with more information.

How to Protect Yourself From Unnecessary Claim Denials

You may not be able to eliminate denials entirely, but you can greatly reduce surprises.

Before you receive care

1. Confirm network status

   • Ask: “Are you in-network with my specific plan name?”
   • Double-check with your insurer if the visit will be covered as in-network.

2. Ask about preauthorization

   • For imaging, procedures, or specialty drugs, ask:
     • “Does this require prior approval from my insurance?”
   • Make sure the provider’s office is actually obtaining it.

3. Request a cost estimate

   • Many providers can give a rough estimate based on your coverage.
   • Ask if they expect any part of the service to be considered non-covered.

4. Keep good records

   • Save:
     • Explanation of Benefits (EOB)
     • Bills
     • Preauthorization approvals
     • Call reference numbers

After you receive care

1. Read the Explanation of Benefits (EOB)

   • This is not a bill. It shows:
     • What was billed
     • What the insurer paid
     • Your share
     • Any denials and reasons

2. Compare the EOB with the medical bill

   • Make sure the denied amount aligns with what your provider is charging you.

3. If something is denied, call both

   • Your insurer – to understand the denial reason in plain terms
   • Your provider’s billing office – to ask if they can correct or resubmit

How to Appeal a Health Insurance Claim Denial

Appeals are a crucial protection, and many denials are changed when challenged properly.

Basic steps to appeal

1. Identify the type of denial

   • Administrative (coding, missing info)?
   • Network issue?
   • Medical necessity?
   • Preauthorization?

2. Review your plan documents

   • Look for the Appeals or Grievances section.
   • Note:
     • Deadlines
     • Required forms
     • Where to send your appeal

3. Gather supporting documents

   • EOB and denial letter
   • Relevant medical records or notes
   • Letters from your clinician explaining why the service was necessary

4. Write a clear, concise appeal letter

   • State:
     • Your name, member ID, claim number
     • The service, date, and denial reason
     • Why you believe it should be covered under your plan
   • Keep copies of everything you send.

5. Track your appeal

   • Note dates, names, and reference numbers for each call.
   • Follow up if you don’t hear back within the stated timeframe.

6. Know that external review may be available

   • In many situations, if your internal appeal is denied, you may have a right to an independent external review outside the insurance company.
   • Check your plan documents and state rules.

Simple Summary: Denials, Insurers, and What You Can Control

While you probably won’t find a universally accepted answer to “Which health insurance company denies the most claims?”, you can understand and manage your risk of denials.

At-a-glance overview

Practical Takeaways When Choosing or Using Health Insurance

To make the denial question work for you, focus on these action steps:

• Ask providers and friends about their experiences with specific insurers in your area.
• Check whether your doctors and hospitals are in-network for the exact plan you’re considering.
• Read the fine print: look at prior authorization, referrals, and coverage exclusions before you enroll.
• Keep documentation of all approvals and communications.
• Appeal thoughtfully when something is denied and you believe it should be covered.

You may never know exactly which health insurance company denies the most claims across the entire system, but you can choose and use coverage in a way that reduces your risk of surprise denials and improves your chances of getting claims paid when you need care.