Eliott Dear: EOB 101 — A Lawyer’s Guide to Reading Your Insurance Statement

An Explanation of Benefits is the single most important document in a billing dispute. Eliott Dear reads dozens every week. Most patients and many physicians do not actually know what the columns mean.

Here is what each piece actually says.

The Header Tells You Who, Not What

The top of every EOB lists the payer name, the subscriber, the patient, the date of service, the rendering provider, the place of service code, the claim number, and the check number. The payer name on the header is often misleading: Anthem HP, LLC might be the envelope, but the actual plan inside could be HealthPlus Medicaid, Empire BCBS, or an employer group plan. Trust the envelope and you miss what decides the path: a Medicaid plan has no IDR path at all, and the plan behind the envelope decides whether the claim belongs in New York State IDR.

The Service-Line Grid Is the Truth

Every EOB has a per-CPT grid. Each row is a service line and each column is an economic fact. The columns vary by carrier format (UHC STD-PRA, Anthem standard, Aetna remit, EmblemHealth, Fidelis) but the core six are always present.

Charge is what the provider billed. Allowed is what the plan deemed reasonable. Not Covered is the difference (your write-off if in-network, your dispute area if out-of-network). Copay/Coins/Ded is the patient responsibility, sometimes broken into three separate columns. Paid is what the plan sent to the provider. Adjustment Codes tell you the why behind any allowed-vs-charge gap.

Copay vs Deductible vs Coinsurance — A Critical Distinction

In adjustment-code language, PR-1 is deductible, PR-2 is coinsurance, PR-3 is copay. Eliott Dear’s standing rule for IDR submissions: PR-3 counts toward what the plan effectively paid; PR-1 and PR-2 do not. A copay is a plan benefit (the carrier expects the provider to collect it but counts it against the allowed amount); a deductible or coinsurance is patient debt the plan has not paid at all.

When the EOB lumps Copay/Coins/Ded into one column without code-level breakdown (common on older Anthem remits), the conservative rule is to credit $0 toward paid.

Spotting an Underpayment

The math is simple. Compare Allowed and Paid per service line to the FAIR Health 80th-percentile UCR for the same CPT and the same geo-zip. A Paid amount well below that benchmark marks a claim worth reviewing, and the wider the gap, the clearer the underpayment dispute. The CPT codes Claims Assassins sees most often in underpayment disputes are 13131, 13132, 13151, 13152 (complex laceration repair), 99281-99285 (ER E/M), 14001-14302 (adjacent tissue transfer), and the anesthesia base codes.

Knowing how to read the EOB is the first hour of any underpayment dispute. Eliott Dear and the Claims Assassins workflow start at the EOB — not the spreadsheet, not the practice management software, not the contract.