An Explanation of Benefits is one of the most misunderstood pieces of mail in health care, mostly because it looks like a bill but isn't one. An EOB comes directly from your insurance company, not your doctor's office, and it's not a request for payment — it's a summary of how your insurer processed a specific claim. * The process behind it: your provider sends a claim to your insurance company after you receive care. Your insurer reviews the claim, applies your specific plan's benefits, and sends you an EOB explaining what happened — while your actual bill, if you owe anything, comes separately from your provider. * Reading an EOB means tracking a few key numbers. The "allowed amount" is what your insurance considers a reasonable charge for that service, which is often lower than what the provider originally billed. The "insurance payment" is how much of that allowed amount your plan actually covered. The "amount owed" is what's left over for you — your deductible, copay, or coinsurance combined. * You'll often see short alphanumeric "remark codes" scattered through the document, each explaining a specific detail about how a charge, payment, or denial was calculated — a key or legend at the bottom of the EOB decodes what each one means. * It's worth holding onto your EOBs at least until the matching bill from your provider arrives, so you can check that the amount you're actually being asked to pay lines up with what your insurer says you owe — discrepancies between the two are one of the most common sources of medical billing errors.