10 Common Medical Billing Errors and How to Spot Them

Billing errors happen more often than most patients realize. Catching mistakes early can save hundreds—even thousands—of dollars. Below are the top 10 errors and what to do about them.

1. Duplicate charges

Sometimes the same procedure is billed twice by mistake. Compare dates and codes; if duplicates appear, request correction.

2. Incorrect patient or insurance info

Mismatched insurance can lead to denied claims or unexpected bills. Verify your insurer and member ID on the bill.

3. Upcoding

A service may be billed at a higher code than performed. If the description doesn't match your care, ask for clarification and an itemized bill.

4. Services not provided

Billing for services you didn’t receive is a clear error—ask for an explanation and remove the charge if confirmed.

5. Unbundling charges

Some facilities bill separate fees for items that should be bundled at a single price. Compare to the contracted or expected rate.

6. Incorrect billing provider

Billing under a different provider or facility can change your financial responsibility. Match provider names to your experience.

7. Missing preauthorization

For certain treatments, prior authorization is required. If a claim is denied for lack of authorization, request an appeal or retroactive approval where appropriate.

8. Failures in applying insurance adjustments

Insurance negotiated adjustments reduce balances; ensure they are applied correctly on your bill.

9. Balance billing & surprise bills

If an out-of-network provider billed you unexpectedly, review recent care and consider disputing if regulations protect you (e.g., federal surprise billing laws).

10. Simple math errors

Yes—sometimes the addition is wrong. Double-check totals and subtotals.

Next steps

Keep calm, gather documents (EOBs, itemized bills), and contact the billing office first. If you need help, patient advocacy groups or state agencies can assist.