How to Fight a Medical Bill: The Ultimate Guide (2025)

Key Takeaways

• Never pay immediately: Always ask for an itemized statement ("Superbill") first.
• Check for codes: Compare the CPT codes on your bill with your Explanation of Benefits (EOB).
• Know your rights: The No Surprises Act protects you from out-of-network charges in emergencies.
• Negotiate: Hospitals often have "charity care" policies or cash-pay discounts if you ask.
• Use AI: Apps like Bill Shield can scan these documents for you to find hidden errors instantly.

If you just opened a medical bill and felt your stomach drop, you are not alone. Millions of Americans overpay for healthcare every year simply because they assume the bill is correct. The reality? Up to 80% of medical bills contain errors.

The good news is that you don't have to be a doctor or a lawyer to fight them. You just need a process. This guide will walk you through the exact steps to audit, dispute, and lower your medical bills.

Step 1: Don't Pay. Request an Itemized Bill.

The bill you receive in the mail is usually a summary. It might say "Lab Services: $500" or "Pharmacy: $200." You cannot fight a summary.

Call the hospital billing department immediately and say this sentence:

"I would like to request an itemized statement with full CPT codes for every line item."

This document (often called a "Superbill") breaks down every single Tylenol, bandage, and minute of doctor time. Once they know you are checking the details, they sometimes lower the bill before sending it, simply because they know they can't justify certain charges.

Step 2: Compare with Your EOB

Your insurance company sends you an Explanation of Benefits (EOB). This is not a bill. It is a receipt of what they covered.

Compare your Itemized Bill with your EOB.

• Did the hospital bill you for something insurance already paid? That is illegal.
• Is there a "Duplicate Charge"? Check if you were billed twice for the same test on the same day.
• Is the "Patient Responsibility" amount the same? If the hospital asks for $1,000 but your EOB says you only owe $200, you only owe $200.

Step 3: Spotting Common Billing Errors

You can manually check for these common tricks, or use the Bill Shield app to scan and detect them automatically:

• Upcoding: This is when a provider bills for a higher level of service than you received. For example, if you saw a nurse for 5 minutes but were billed for a "Level 5 Emergency Visit" (Code 99285).
• Unbundling: Some procedures should be billed as one package. Unbundling breaks them apart to charge you more.
• The "Out-of-Network" Trap: If you went to an in-network hospital for surgery, but the anesthesiologist was out-of-network, you might get a surprise bill. Under the No Surprises Act, this is often illegal for emergency services.

Step 4: Send a Dispute Letter

If you find an error, do not just call. Write it down. Sending a formal dispute letter creates a paper trail that forces the hospital to respond legally.

Your letter should include:

1. Your account number and date of service.
2. The specific line item you are disputing.
3. The reason (e.g., "Duplicate Charge," "Incorrect Coding").
4. A request to pause billing while the dispute is investigated.

Conclusion

Fighting a medical bill takes patience, but the savings are real. You are your own best advocate. If this process sounds overwhelming, you can download Bill Shield to handle the scanning, code-checking, and letter-writing for you automatically.