How do I dispute a medical billing error?

Request an itemized bill, compare it to your EOB, identify the specific error, and contact the billing department in writing. Include your account number, a description of the error, and supporting documentation. Keep records of all communications.

How long do I have to dispute a medical bill?

There is no universal time limit for disputing a bill, but you should act quickly. Most providers send bills to collections after 90-180 days. File disputes as soon as you identify an error.

10 Most Common Medical Billing Errors and How to Spot Them

How Common Are Medical Billing Errors?

Research from medical billing advocates and consumer groups consistently finds that a significant percentage of medical bills contain errors. Some estimates suggest that 30-80% of bills have at least one mistake, though the exact figure depends on the study and methodology. Even a small coding error can add hundreds or thousands of dollars to your bill. Checking your bill carefully is not paranoia — it is practical self-defense.

1. Duplicate Charges

The same service appears on your bill twice. This happens most often in hospital settings where multiple departments enter charges. Look for identical CPT codes with the same date of service.

2. Upcoding

A more expensive code is used than the service you actually received. For example, being billed for a Level 5 office visit (99215) when you had a routine 15-minute appointment. Compare the service description to what actually happened.

3. Unbundling

Services that should be billed under a single bundled code are billed separately at higher individual prices. For example, billing each component of a blood panel individually instead of using the panel code.

4. Incorrect Patient Information

Wrong date of birth, insurance ID, or name can cause claims to be denied or processed incorrectly. Always verify your personal information on every bill.

5. Balance Billing for In-Network Services

Your provider bills you for the difference between their charge and the insurance-allowed amount, even though they are in-network. Under the No Surprises Act (2022), this is illegal for most in-network services and many emergency services.

6. Services Not Rendered

Charges for procedures, tests, or supplies you never received. This can happen when orders are placed but canceled, or through outright error.

7. Incorrect Quantity

Being billed for five units of a medication when you only received one, or being charged for three physical therapy sessions when you attended two.

8. Operating Room Time Errors

Hospitals bill by the minute for OR time. Errors in start and end times can add thousands of dollars. Request the anesthesia record to verify actual procedure duration.

9. Wrong Diagnosis Code

An incorrect ICD-10 code can cause a claim to be denied for lack of medical necessity, leaving you responsible for the full charge. Ask your doctor to verify the diagnosis code matches your condition.

10. Out-of-Network Billing for In-Network Facilities

You go to an in-network hospital but are treated by an out-of-network specialist without your knowledge. The No Surprises Act protects you in most of these situations — you should only owe your in-network cost-sharing amount.