How to audit a hospital bill for errors?

Hospital billing errors are far more common than most people realize. Studies have found error rates ranging from 30% to 80% on hospital bills. The more complex the care, the higher the chance of mistakes. Auditing your bill before you pay can save you hundreds or thousands of dollars.

Step 1: Get an itemized bill. The summary bill that most hospitals send first just shows a total amount. You need the itemized version that lists every individual charge with billing codes (CPT codes for procedures, ICD codes for diagnoses, and HCPCS codes for supplies). Call the billing department and request an itemized statement. You have a legal right to this under the No Surprises Act and under most state laws.

Step 2: Compare with your Explanation of Benefits. Your insurance company sends an EOB for each claim processed. Compare the charges on the hospital's itemized bill with what your insurance was billed. Look for charges that weren't submitted to insurance, procedures that were denied but shouldn't have been, and discrepancies between what the hospital says you owe and what the EOB says.

Step 3: Look for common errors.

Duplicate charges: Being billed twice for the same procedure, test, or medication. This is especially common during long hospital stays where shift changes can cause duplicate entries.

Upcoding: Being charged for a more expensive procedure or room than you actually received. For example, being billed for a private room when you were in a shared room, or being charged for a complex office visit (CPT 99215) when a standard one (CPT 99213) is more appropriate.

Unbundling: Billing separately for components that should be covered under a single code. Some procedures include multiple steps in a single billing code, and billing each step individually inflates the total.

Operating room time: OR charges are billed in increments (often 15 or 30 minutes). Compare the billed time with your surgery record. A 45-minute procedure shouldn't be billed for 2 hours of OR time.

Medications and supplies: Check that you actually received the medications listed. Generic drugs billed at brand-name prices is a common issue. Charges for supplies that are standard in any procedure (gloves, gowns, basic dressings) should generally be included in the facility fee, not billed separately.

Step 4: Dispute errors. Call the billing department with specific line items you're questioning. Be polite but firm. Reference the specific charges and codes. If they won't correct errors, file a written dispute and send copies to your insurance company. You can also file complaints with your state's Attorney General or Department of Insurance.

If the bill is very large ($10,000+), consider hiring a medical billing advocate. They typically charge 25% to 35% of the savings they find, so they only get paid if they save you money.