5 Common Medical Bill Errors That Cost You Thousands
Up to 80% of medical bills contain errors, according to the Medical Billing Advocates of America. But most patients pay without questioning a single line item. These are the five most common billing errors that cost patients thousands — and how to catch each one.
Duplicate Charges
The same service billed twice on the same date. This is the most straightforward error to catch and the easiest to get removed.
Real example: A patient's bill showed two charges for CPT 85025 (Complete Blood Count) on the same date — $350 each. Only one blood draw was performed. The duplicate was removed, saving $350.
How to catch it: Look for identical CPT codes on the same date of service. Unless there's a documented medical reason for performing the same test twice (rare), it's a duplicate.
Upcoding
Being billed for a more expensive version of a service than what you actually received. This is most common with emergency room visits and office visits, where services are coded on a 1–5 complexity scale.
Real example: A patient visited the ER for a sore throat, was seen for 10 minutes, and received a strep test. The bill coded it as a Level 5 visit (99285 — reserved for life-threatening emergencies) at $4,250 instead of a Level 2–3 visit at $500–$800. Difference: over $3,000.
How to catch it: Look at the ER or office visit code level. If you were seen for a minor issue and the bill says Level 4 or 5, compare it to what actually happened during your visit. Request the medical decision-making documentation to verify.
Extreme Overcharges
Hospitals set their own prices (called the “chargemaster”), and those prices often have no connection to what the service actually costs or what insurance companies pay. Some charges exceed typical commercial insurance rates by 10x, 20x, or even 40x.
Real example: A Complete Blood Count (CBC) — one of the most common lab tests — was billed at $350. The CMS Medicare rate for a CBC is $7.77, and commercial insurance typically reimburses $12–$19. That's a 45x markup over Medicare.
How to catch it: Look up the CMS Medicare rate for each CPT code on your bill. If the charge exceeds 2.5x the Medicare rate, it's above even typical commercial insurance reimbursement and is worth disputing.
Unbundling
Billing separately for services that should be grouped under a single code. Unbundling artificially inflates the total by treating one service as multiple billable items.
Real example: A patient was charged $950 for IV infusion (96360) plus $800 for normal saline (J7030) as a separate line item. Saline is a standard component of IV infusion and is included in the infusion code — billing it separately is textbook unbundling. The $800 saline charge should be removed.
How to catch it: Look for supply charges alongside procedure charges. Common unbundling patterns include saline billed separately from IV infusion, surgical tray charges alongside procedure codes, and specimen handling fees alongside lab work.
Phantom Charges
Being billed for services you never received. This can include medications that were ordered but never administered, procedures that were cancelled but still charged, or supplies that were never used.
Real example: A patient was billed for a physical therapy session that was scheduled but cancelled when they were discharged early. The cancellation was never communicated to billing, and the charge remained on the bill for $450.
How to catch it: Go through every line item and ask yourself: “Did this actually happen?” If you don't remember a service, request your medical records and check whether it's documented. If it's not in the records but it's on the bill, it's a phantom charge.
What to Do If You Find Errors
If you spot any of these errors on your bill, here's the short version of what to do:
- Don't pay yet. You have time — most providers allow 30–90 days before escalating.
- Call the billing department and reference the specific CPT codes and charges you're questioning.
- Send a formal dispute letter via certified mail with the errors documented, Medicare benchmark rates cited, and a 30-day deadline for response.
- Follow up. If you don't hear back in 30 days, escalate to the hospital patient advocate, your insurance company, or your state's Attorney General.
For a complete walkthrough, read our step-by-step guide to disputing a medical bill.
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Scan Your Bill Free →Disclaimer: This guide is for informational purposes only and does not constitute legal or financial advice. Consult a healthcare billing professional or attorney for advice specific to your situation.