How do I read an EOB or 835 remittance?
An EOB (or its electronic form, the 835 ERA) shows, per claim line, what you billed, what the payer allowed, what it paid, and why any amount wasn't paid — the last part carried in CARC and RARC codes. The key habit is comparing the allowed amount to your contracted rate on every line, because a claim can pay in full and still be underpaid.
What actually matters
- Billed vs. Allowed vs. Paid: 'allowed' is the contracted amount; 'paid' is allowed minus patient responsibility and any adjustments
- CARC codes explain adjustments and denials (e.g. CO-45 contractual, CO-197 no auth); RARC codes add detail
- 'CO' means contractual (provider write-off), 'PR' means patient responsibility, 'OA'/'PI' are other adjustments — the group code matters as much as the number
- Compare the allowed amount to your contracted fee schedule, not just to zero — a paid claim below contract is a silent underpayment
- Reconcile the 835 to your posted payments so nothing is mis-posted or missed
Common questions
What is the difference between an EOB and an 835?
They carry the same information. The EOB is the human-readable explanation of benefits; the 835 (ERA) is the electronic remittance file your clearinghouse or PM system posts automatically.
What does CO-45 mean on a remittance?
CO-45 is a contractual adjustment — the difference between your billed charge and the payer's allowed amount, written off under your contract. It's normal, but if the allowed amount itself is below your contracted rate, that's a recoverable underpayment.
Where Volari fits: Volari reads every line of your 835s the way most practices never have time to — comparing paid and allowed against what you were actually owed.
See the revenue you're owed but never collected.
A free assessment shows your real recoverable number from denied and underpaid claims. No risk, paid only on what we recover.