Common Medical Billing Errors and How to Spot Them

What are medical billing errors?

Medical billing errors are mistakes on hospital or provider bills that result in patients being charged incorrectly. Industry experts and patient advocacy groups estimate that a significant percentage of medical bills contain at least one error, though exact figures vary by study and setting. These errors range from simple typos to systematic upcoding that inflates charges by hundreds or thousands of dollars.

If you have ever looked at a medical bill and felt confused by the charges, you are not alone. The Consumer Financial Protection Bureau reported in 2022 that approximately 43 million Americans had medical debt on their credit reports, and billing errors contribute to this problem when patients pay incorrect charges or when disputed bills go to collections.

Why do billing errors happen?

Medical billing is complex. A single hospital visit can generate dozens of individual charge codes across multiple departments. The transition from ICD-9 to ICD-10 coding expanded the number of diagnosis codes from approximately 13,000 to over 68,000, dramatically increasing the chance of miscoding.

Common causes include:

• Manual data entry mistakes during registration or charge capture
• Upcoding where a provider bills for a more expensive service than what was performed
• Unbundling where services that should be billed under a single code are split into separate charges
• Duplicate billing for the same service, especially after transfers between departments
• Incorrect patient information such as wrong insurance ID or date of birth

The 7 most common errors on medical bills

1. Duplicate charges

Duplicate charges occur when the same procedure or service appears more than once on your bill. Patient advocacy groups report that duplicate charges are among the most frequently found billing errors. This happens frequently during hospital stays when shift changes result in the same test being entered twice.

How to spot it: Look for identical line items with the same date of service and CPT code. If you see the same charge listed twice, flag it immediately.

2. Incorrect CPT or diagnosis codes

Current Procedural Terminology (CPT) codes identify specific medical procedures. When the wrong code is used, you may be charged for a procedure you never received. For example, a 15-minute office visit (CPT 99213) billed as a 40-minute comprehensive visit (CPT 99215) can result in a significantly higher charge.

How to spot it: Request an itemized bill and cross-reference each CPT code with the services you actually received. Our free bill reader tool can help decode these codes instantly.

3. Upcoding

Upcoding is when a provider bills for a more expensive service or procedure than what was actually provided. The HHS Office of Inspector General has consistently identified upcoding as one of the top sources of improper Medicare payments.

How to spot it: Compare the complexity level of your visit with the code billed. Emergency room visits are particularly prone to upcoding — if a straightforward ER visit for a minor issue is billed at the highest severity level (CPT 99285), that warrants a closer look.

4. Unbundled charges

Some procedures include related services that should be billed together under a single bundled code. Unbundling splits these into separate line items, inflating the total. For example, a surgical procedure that includes standard prep work should not have the prep billed as a separate charge.

How to spot it: Look for multiple charges on the same date that seem related to a single procedure. If you had surgery, you should not see separate charges for standard surgical supplies that are typically included.

5. Balance billing errors

Balance billing occurs when an out-of-network provider bills you for the difference between their charge and what your insurance paid. Under the No Surprises Act (effective January 1, 2022), balance billing is illegal for emergency services and certain non-emergency services at in-network facilities.

How to spot it: If you received emergency care or treatment at an in-network hospital, you should not see balance bills from individual providers. If you do, this may be an illegal charge under federal law.

6. Incorrect patient information

Wrong insurance ID numbers, misspelled names, or incorrect dates of birth can cause claims to be denied entirely, leaving you with the full bill. The Healthcare Financial Management Association (HFMA) has identified incorrect demographic and insurance information as a leading cause of claim denials.

How to spot it: Check the top section of every bill and EOB for your correct name, date of birth, insurance ID, and group number. Even a single digit error can result in denial.

7. Charges for services not rendered

This includes being billed for tests that were ordered but cancelled, medications that were prescribed but never administered, or room charges for days after discharge.

How to spot it: Keep a personal log during any hospital stay noting tests, medications, and procedures. Compare this against your itemized bill line by line.

How to dispute a medical billing error

If you find an error on your bill, take these steps:

1. Request an itemized bill. By law, you are entitled to a detailed breakdown of all charges. General summary bills are not sufficient for error detection.
2. Contact the billing department. Call the provider's billing office and reference the specific line items in question. Document the date, time, and name of everyone you speak with.
3. File a formal dispute in writing. Send a written dispute via certified mail. Include copies of your itemized bill with the errors highlighted and any supporting documentation.
4. Contact your insurance company. If the error involves insurance processing, file a complaint with your insurer. They have a financial incentive to correct overbilling.
5. File a complaint with your state. If the provider does not resolve the issue, file a complaint with your state's Department of Insurance or Attorney General's office.

Use our free tool to decode your bill

Medical bills are deliberately complex, but they do not have to be. Upload your medical bill or EOB to our free Medical Bill Reader tool, and we will break down every charge, identify potential errors, and explain your costs in plain language. No signup required, and your documents are processed privately in your browser.

FAQ

How common are medical billing errors?

Estimates vary widely depending on the study and methodology. Patient advocacy organizations have cited error rates as high as 80%, while more conservative insurance industry estimates are lower. The key takeaway is that billing errors are common enough that reviewing your itemized bill is always worthwhile.

Can medical billing errors affect my credit score?

Yes. If an incorrect charge goes to collections, it can appear on your credit report. Starting July 1, 2022, the three major credit bureaus (Equifax, Experian, TransUnion) stopped reporting paid medical debt and removed medical collections under $500 from credit reports. However, larger erroneous charges that go unpaid can still cause damage.

How long do I have to dispute a medical bill?

Most states allow 30-180 days to dispute charges, but timelines vary. Federal law requires insurers to have an internal appeals process. Check your state's specific statute of limitations for medical debt disputes.

Should I hire a medical billing advocate?

For large hospital bills, a professional medical billing advocate can be worthwhile. They typically charge a percentage of the savings they find. For smaller bills, using a free tool like Medical Bill Reader to understand your charges is a good first step before deciding whether professional help is needed.