Up to 80% of medical bills contain errors, but the average patient cannot detect them because Explanation of Benefits documents use opaque CPT codes with no plain-language description of what was actually done

Studies consistently find that 49-80% of medical bills contain at least one error, and the average hospital bill over $10,000 includes approximately $1,300 in overcharges. Yet fewer than half of patients who suspect a billing error actually contact their provider or insurer to dispute it. Of those who do, 74% get the error corrected — proving the errors are real and fixable, if only the patient can identify them. This matters because the primary document patients receive — the Explanation of Benefits (EOB) — is designed for payer-provider communication, not patient comprehension. It lists services as five-digit CPT codes (like '99214' or '73721') with minimal or no description of what the service actually was. A patient who had a knee examined cannot tell whether code 73721 (MRI without contrast) is correct or whether they were billed for code 73723 (MRI with and without contrast, which costs $400-$800 more). The EOB shows 'allowed amount,' 'provider charge,' 'plan payment,' and 'your responsibility' — but does not explain why the provider charged $3,200 when the allowed amount is $800, or what the patient can do about it. Patients receive multiple EOBs for a single visit — one for the doctor, one for the facility, one for the lab, one for the anesthesiologist — and are expected to reconcile these against provider bills that arrive on different dates with different account numbers. This problem persists because there is no regulatory requirement that EOBs include plain-language service descriptions that a patient can verify against their actual experience. CMS and state insurance departments regulate EOB content, but the regulations focus on financial accuracy (did the math add up?) rather than patient comprehensibility (can the patient tell if they were billed for the right thing?). Insurers have no financial incentive to make EOBs more transparent because confused patients who do not dispute bills save the insurer the cost of reprocessing claims. Providers have no incentive because clearer bills would increase dispute rates. The patient is the only party who benefits from comprehensibility, and the patient has no power to change the format.