What is the difference between a medical bill and an EOB?

A medical bill comes from your healthcare provider and shows what you owe. An Explanation of Benefits (EOB) comes from your insurance company and shows what was billed, what insurance paid, and what you are responsible for. Always compare the two — they should match.

What does 'adjustment' mean on a medical bill?

An adjustment is the discount your insurance company negotiated with the provider. If your insurer has a contract with the hospital, the hospital agrees to accept a lower rate than its list price. The adjustment is the difference between the billed amount and the allowed amount.

Can I negotiate my medical bill?

Yes. Many providers offer payment plans, financial assistance programs, or discounts for paying in full. You can also negotiate specific charges, especially if you can show that the price exceeds the fair market rate for your area.

How to Read a Medical Bill: Line-by-Line Guide

Why Medical Bills Are So Confusing

Medical bills are written for insurance companies and billing departments, not patients. They use standardized codes, abbreviations, and layouts that assume you already understand the healthcare billing system. A single emergency room visit can generate separate bills from the hospital, the attending physician, the radiologist, and the lab — each with its own format. Understanding the structure of a medical bill is the first step toward catching errors, negotiating charges, and avoiding collections.

Patient Information and Account Details

The top of your bill shows your name, account number, medical record number (MRN), and the date of service. Check these carefully — billing errors often start with wrong patient data or incorrect dates. Your insurance information should also appear here. If the insurance section is blank or shows the wrong plan, the bill may not have been submitted to your insurer at all.

Service Descriptions and CPT Codes

Each line item on your bill represents a service, procedure, or supply. These are identified by CPT (Current Procedural Terminology) codes — five-digit numbers like 99213 (office visit, established patient) or 99283 (emergency department visit, moderate severity). The description next to the code should roughly match what happened during your visit. If you see codes for services you did not receive, flag them immediately.

Charges, Adjustments, and Insurance Payments

The 'charge amount' or 'billed amount' is the hospital's list price — almost no one pays this full amount. The 'adjustment' column shows the discount your insurance company negotiated. The 'insurance payment' shows what your insurer actually paid. The remaining 'patient responsibility' is what you owe, which includes your copay, coinsurance, and any charges applied to your deductible.

Understanding Your Balance Due

Your balance due is the total amount the provider expects you to pay after insurance adjustments and payments. This should equal the sum of your copays, coinsurance amounts, and deductible charges. If the balance seems too high, compare it to your insurance company's Explanation of Benefits (EOB) — the numbers should match. Discrepancies often indicate a billing error or a claim that was not processed correctly.

Common Red Flags on Medical Bills

Watch for duplicate charges (the same service billed twice), upcoding (a more expensive code than the service actually provided), unbundling (billing separately for services that should be grouped under one code), and balance billing (charging you the difference between the billed amount and the insurance-allowed amount, which is illegal for in-network providers in most states under the No Surprises Act). If you spot any of these, contact the billing department and request an itemized statement.

What to Do If You Think There Is an Error

Request an itemized bill if you do not already have one. Compare every line to your EOB. Call the billing department and ask them to explain any charge you do not understand — you have the right to a clear explanation. If the provider cannot resolve the issue, file a complaint with your state insurance commissioner or contact a patient advocate. Do not ignore a bill you believe is wrong, as unpaid balances can be sent to collections.