Getting a coverage denial or an unexpected medical bill is frustrating. You have rights, and there's a clear path to push back. If your health plan refused to pay for a service you thought was covered, or a provider sent you a bill that looks wrong, act fast, stay systematic, and put everything in writing. Disputing a bill is a normal part of how the system works. The goal is to avoid paying for a service that should have been covered or was charged in error.
First, figure out what kind of dispute you're in. A coverage denial means your health plan decided a service wasn't medically necessary, wasn't covered, or wasn't pre-approved. A billing dispute involves charge errors, duplicate billing, or services you never got. Each needs a slightly different approach, but both start with verification and documentation.
Gather Your EOB and Medical Bill
Before you dispute anything, collect your documents. You'll need:
- Your Explanation of Benefits (EOB) from your health plan. It shows what was billed, what was covered, and why it was denied.
- The medical bill from your provider, showing the actual charges for services.
- Your plan documents or Summary of Benefits and Coverage (SBC), to verify coverage and exclusions.
- Any prior authorization letters or referral notes, if you have them.
Compare the EOB and the bill side by side. A common mistake: a provider bills more than the allowed amount, or you get a bill before your insurance has finished paying. If the amount on the bill doesn't match what the EOB says you owe, call the provider first, before disputing with your insurance.
How to Dispute a Coverage Denial
If your plan denied coverage, start by understanding exactly why. The EOB includes a denial code and a brief explanation. Typical reasons include a finding that the service was not medically necessary, that it was experimental, that the provider was out of network, or that pre-authorization was missing. Once you know the why, you can build your case.
Step 1: File an Internal Appeal
Most employer-sponsored plans fall under ERISA (Employee Retirement Income Security Act), which gives you the right to appeal. Here's how:
- Read the denial letter carefully. It includes the appeal deadline. ERISA requires plans to give you at least 180 days from when you receive the denial.
- Call your plan's customer service to confirm the process and ask for the full claims file, including the clinical criteria they used.
- Write a formal appeal letter with your name, member ID, claim number, the denied service, and why you think the denial was wrong. Include supporting evidence like:
- Medical records, doctor's notes, or letters from your provider explaining why the service was necessary.
- Copies of plan documents showing the service is covered.
- Any prior authorization numbers or communications.
- Send the appeal via certified mail or through your plan's online portal if they allow it. Keep copies of everything.
- Wait for a decision. The plan must respond to an urgent appeal within 72 hours. For non-urgent appeals, the deadline is 30 days for pre-service claims and 60 days for post-service claims. If they deny again, you can request an external review.
Step 2: Request an External Review
If the internal appeal is denied, the Affordable Care Act requires most non-grandfathered plans to offer an independent external review. The denial letter will explain how to request one, and you must file within four months of receiving the final internal denial. An independent third party will review your case, and their decision is binding on the plan. It's a strong tool. Insurers often reverse decisions at this stage. You can also contact your state's Department of Insurance or the U.S. Department of Labor for help.
How to Dispute a Medical Bill
If your dispute is about the bill itself rather than the insurance denial, start with the provider. Billing errors are common, especially after a complex procedure.
- Review the bill for errors. Common mistakes include:
- Duplicate charges for the same service.
- Services you never received.
- Wrong procedure codes or ICD-10 codes.
- Balance billing from an out-of-network provider at an in-network facility.
- Call the provider's billing department. Politely explain the discrepancy. Ask for an itemized bill if you didn't get one. Many errors get resolved with a simple phone call. WellthCare's Health-to-Wealth system includes medical bill review and cost transparency tools that can catch those errors before they reach you, reducing frustration and unnecessary charges.
- File a formal written dispute. If the call doesn't fix it, send a letter to the provider's billing manager and the hospital's patient advocate. Include copies of the bill, your EOB, and any correspondence. Request a corrected bill.
- Consider a payment plan or financial assistance. If the bill is correct but you can't pay, many hospitals offer charity care or income-based discounts. Ask about their financial assistance policy.
- Report violations. If you think you've been unfairly balance-billed or charged for services that should have been covered, file a complaint with your state's insurance commissioner or the federal No Surprises Help Desk at 1-800-985-3059.
Key Protections You Should Know
- The No Surprises Act (2022) protects you from surprise out-of-network bills for emergency services and certain non-emergency care at in-network facilities. If you get a surprise bill, call the provider and your plan. The Act may require them to fix it.
- HIPAA Privacy Rules give you the right to access your medical records, which can help prove medical necessity in a denial dispute.
- ERISA and ACA protections guarantee your right to appeal and request an external review. ERISA Section 510 also bars employers from retaliating against you for exercising your plan rights.
- State consumer protection laws may offer additional rights, especially for fully insured plans. Check with your state's insurance commissioner.
Medical Debt and Your Credit Report
The main driver of urgency while a bill is in dispute is whether it will show up on your credit report and hurt your score. The answer has changed twice in recent years, and the current rules are more protective than most people assume.
In January 2025 the Consumer Financial Protection Bureau finalized a rule that would have banned medical debt from credit reports entirely. A federal court in Texas vacated that rule on July 11, 2025, so it never took full effect and medical debt can still be reported today. What still applies is a set of voluntary changes the three nationwide bureaus put in place. Equifax, Experian, and TransUnion no longer report paid medical collections or collections with an initial balance under $500, and they wait 365 days before adding a new unpaid medical collection to your report.
While you dispute a bill, you usually have time. The 365-day window gives you room to file your appeal, request a corrected bill, or apply for financial assistance before a collection appears. If a medical collection does show up while you're still disputing it, you can dispute the account directly with the credit bureau under the Fair Credit Reporting Act, just as you dispute the bill with the provider.
When to Get Help
If the process feels too complex or the amount is significant, you can get help from:
- Patient advocates. Many nonprofits and private services offer dispute assistance.
- State Health Insurance Assistance Programs (SHIPs). These are especially helpful for Medicare-related disputes.
- An attorney. If you're facing a large denial related to a chronic condition or serious illness, a health law attorney can be worth the investment.
- Your employer's HR/Benefits team. Since many employer plans are self-funded, your HR team may have direct sway with the plan administrator and can escalate internally.
Disputing a coverage denial or medical bill is a learned skill, but you don't need to be an expert. Stay organized, stick to deadlines, and don't give up. Most errors and denials are reversible when you follow the right process. And remember: the system works best when you advocate for yourself, persistently and patiently.