How to Read an Explanation of Benefits (EOB): A Patient's Guide

Rule #1: An EOB Is Not a Medical Bill

The prominent text printed across the top of almost every document from your insurer says: **"THIS IS NOT A BILL."**

Believe it. An Explanation of Benefits (EOB) is an informational statement detailing how an insurance company processed a medical claim submitted by your physician, lab, or hospital. It explains what services were performed, how much was billed, the contracted discount, what the plan paid, and what you may owe based on your policy's cost-sharing requirements.

Paying a hospital bill before reconciling it with your EOB is one of the most common ways patients overpay for medical care.

Decoding the Core Columns on Every EOB

While every insurance company formats its EOB slightly differently, they all share standardized financial columns:

1. Billed Amount (Charges) The retail price the healthcare provider submitted for the service. Hospitals often set this figure artificially high.

2. Allowed Amount (Contracted Rate) The maximum dollar figure the insurer agrees is reasonable for the specific procedure code under their contract with in-network providers.

3. Provider Discount / Write-Off The difference between the Billed Amount and the Allowed Amount. If the provider is in-network, they are contractually obligated to write this amount off. You can never be billed for this difference.

4. Paid by Insurer The exact dollar sum your health insurance plan transmitted directly to the medical facility or doctor.

5. Patient Responsibility (You May Owe) The total remaining balance that you are responsible for paying. This is further broken down into deductible, copayment, or coinsurance.

Understanding Your Cost-Sharing Obligations

Your "Patient Responsibility" figure is governed by your plan's coverage rules:

• **Deductible:** The annual amount you must pay out-of-pocket before insurance benefits kick in.
• **Copay (Copayment):** A fixed flat dollar fee paid per visit or prescription (e.g., $30 for a specialist).
• **Coinsurance:** A percentage split between you and your insurer after meeting your deductible (e.g., insurer pays 80%, you pay 20%).
• **Out-of-Pocket Maximum (OOPM):** The absolute cap on what you will pay for covered in-network care in a calendar year. Once reached, the plan pays 100% of allowed charges.

How to Spot Denied Line Items & Remark Codes

If the insurer refused to cover a specific charge, the "Paid by Insurer" column will display **$0.00**, and the amount will shift into your patient responsibility column or a "Non-Covered" column.

Look at the footnote column (labeled **Notes**, **Remarks**, or **Code**): - You will see a 2-to-4 character code such as **CO-50**, **PR-96**, or **CO-16**. - Scroll to the bottom of the page or the last page of the EOB for the "Remarks Legend" to read the explanation associated with that code.

A 5-Step EOB Verification Checklist

1. **Verify Patient & Provider Name:** Confirm the service was actually rendered to you or your covered dependent.
2. **Compare Date of Service:** Ensure there are no duplicate claims for the same appointment date.
3. **Check for Contractual Write-Offs:** Ensure the provider isn't balance-billing you for the difference between the retail charge and the allowed amount.
4. **Audit Your Deductible Total:** Verify that your payments were correctly credited toward your annual deductible tracker.
5. **Flag Any $0.00 Paid Lines:** If a legitimate service was denied, initiate an appeal before paying the doctor's invoice.