An Explanation of Benefits (EOB) is the document a payer sends after processing a claim, showing exactly how they arrived at the payment amount — or the denial. Reading one correctly is a basic but essential skill for anyone working claims follow-up.
The key fields to look at, in order: the billed amount (what was originally charged), the allowed amount (what the payer’s contract actually permits for that service), any adjustment or write-off amount (the difference between billed and allowed, which the practice cannot collect from the patient), the amount the payer actually paid, and the patient responsibility (copay, coinsurance, or deductible still owed).
The field that causes the most confusion is the reason code or remark code section — a short alphanumeric code explaining any reduction or denial. These codes are standardized across payers (CARC and RARC codes), which means once staff learn to recognize the common ones for their specialty, EOBs become far faster to process. Keeping a simple internal reference sheet of the reason codes that show up most often — and what action each one requires — saves significant time compared to looking each one up individually.