Understanding Medical Bills and How to Dispute Them

Updated March 28, 2026 • 10 min read • By National Healthcare Connect

Step 1: Understand the Documents You'll Receive

Medical billing involves multiple documents — and confusing them leads to mistakes:

• Explanation of Benefits (EOB): Sent by your insurance company — NOT a bill. Shows what was billed, what insurance paid, and what you may owe. "This is not a bill" is often printed on it.
• Medical bill: Sent by the provider (hospital, doctor's office, lab). This is what you actually owe. Wait until you receive an EOB from your insurer before paying any bill.
• Itemized bill: A line-by-line list of every charge. Always request this — standard bills often show only summary amounts.

Rule: Never pay a medical bill until you've received and reviewed the EOB from your insurance company.

Step 2: Request an Itemized Bill

You have the legal right to request an itemized bill. Call the billing department and ask for "a complete itemized bill with CPT codes and diagnosis codes." Providers are required to provide this.

Review each line for:

• Duplicate charges: Being billed twice for the same service
• Services not received: Procedures or medications listed that you don't recall receiving
• Upcoding: Billing for a more expensive procedure than what was performed
• Unbundling: Charging separately for procedures that should be billed together at a lower rate
• Wrong dates or patient info: Bills applied to the wrong patient, wrong date of service

Step 3: Compare the Bill to Your EOB

The amounts on your itemized bill should match what your insurer processed. Look for:

• Services your insurance should have covered but denied
• Incorrect network status (you used an in-network provider but were billed out-of-network rates)
• Services that should apply to your deductible but weren't applied correctly
• Co-pay amounts that differ from your plan's schedule

Step 4: How to Dispute a Medical Bill

Disputing a billing error with the provider

1. Call the billing department (not the front desk). Identify the specific error by line item and charge code.
2. Ask them to resubmit the corrected claim to your insurance or remove the duplicate charge.
3. Document every call: date, time, name of person, what was discussed, what they agreed to do.
4. Follow up in writing (email or certified mail) confirming what was discussed.
5. Request written confirmation of any correction or credit.

Appealing an insurance denial

If your insurer denied a claim you believe should be covered:

1. Request the specific denial reason in writing (code and explanation).
2. File an internal appeal with your insurer — you generally have 180 days from the denial.
3. Ask your doctor to write a letter of medical necessity if the denial was for a covered service deemed "not medically necessary."
4. If the internal appeal fails, request an external independent review — you have this right under the ACA.

Step 5: Negotiate What You Actually Owe

Even correct bills can often be reduced:

• Ask for the cash-pay rate: Uninsured rates are often dramatically lower than insurance-billed rates. If you're uninsured or the bill wasn't processed by insurance, ask what the self-pay discount is.
• Apply for financial assistance: Hospitals are required to have charity care programs. Ask specifically: "Do you have a financial assistance program, and can I apply?" Income limits vary, but these programs are underutilized.
• Negotiate a lump sum settlement: If you owe $2,000 and can pay immediately, offer $1,200–$1,400 in a lump sum. Many billing departments have discretion to accept.
• Set up a payment plan: Hospitals cannot send you to collections while you're on an active payment plan. Even small monthly payments protect your credit.

Know Your Rights

• Hospitals cannot send you to collections for a bill you are actively disputing
• The No Surprises Act (2022) limits balance billing from out-of-network providers in emergency situations
• You can request an itemized bill regardless of how the provider presents the initial bill
• Medical debt under $500 cannot be reported to credit bureaus (new CFPB rules, 2025)
• You can file a complaint with your state's insurance commissioner or health department if a provider or insurer acts in bad faith