An Explanation of Benefits, or EOB, is a statement your insurer provides after processing a claim. It is not a bill but a detailed breakdown of how your claim was adjudicated. The EOB typically shows the date of service, the provider, the amount charged, the eligible amount (after reasonable-and-customary adjustments), the deductible applied, the co-insurance or co-pay amount, the amount the insurer paid, and any amount you owe. If a claim is partially or fully denied, the EOB will include the reason — such as "benefit maximum reached," "excluded condition," or "waiting period applies." EOBs are essential for understanding your benefits usage, tracking remaining maximums, and identifying errors. They are also needed when coordinating benefits between two plans.