he Explanation of Benefits is not a bill. It is a notice. Most people file it. A lot of people should read it, because one field, "patient responsibility," is where billing errors hide. Six fields on this document actually matter. The rest is noise.
I.
The six fields that matter
- Date of service: match to your calendar. If the date is wrong, the claim is wrong.
- Provider / CPT code: the five-digit code that identifies the procedure. Look it up; confirm it matches what you received.
- Billed: what the provider charged. This is the chargemaster rate and is almost always inflated.
- Allowed: what your insurance agreed the procedure is worth. Contract rate.
- Paid: what insurance sent to the provider.
- Patient responsibility: your copay, coinsurance, or deductible hit. This is the number you're liable for.
The math that should always check out: Allowed - Paid = Patient responsibility (minus any non-covered amount). If patient responsibility is higher than Allowed - Paid, there's a coding or benefit error.
II.
Cross-check against the itemized bill
Request an itemized bill from the provider (they're required to provide one). Line-by-line, confirm each service on the bill matches a line on the EOB. Any service on the bill that isn't on the EOB is either a mistake or wasn't submitted to insurance, so call and ask.