How to read an 835 remittance (ERA)

A plain-language walkthrough of the 835 electronic remittance advice: the payment header, claim and service lines, and the adjustment codes that explain each one.

By PayerBeacon. Published October 17, 2026. Updated October 20, 2026.

How do I read an 835 remittance?

Start with the payment header, then read each claim and service line, then use the CAS adjustment segments to see why the payer paid what it did.

It depends. If you only need the total paid, read the BPR and CLP segments. If a line looks low, read its SVC and CAS segments before comparing it with your contract. If the adjustment codes are unfamiliar, start with the CARC guide.

What an 835 is

The 835 is the ANSI X12 electronic format a payer uses to tell a practice what it paid and why. It is the electronic remittance advice, or ERA, and it carries the same information as a paper explanation of benefits (EOB) in a form software can read.

One 835 file usually covers a batch of claims paid together, so a single file can hold many claims and many service lines.

The parts to find first

The BPR segment holds the total payment amount and the payment method, and the TRN segment holds the trace number that ties the remittance to the deposit.

Each claim starts with a CLP segment, which gives the claim identifier, the claim status, the total billed charge, and the amount paid. Under it, each SVC segment is one service line with its procedure code, the billed charge, and the paid amount.

CAS segments carry the adjustments. Each one names a group code, a reason code, and an amount. The group code says who the adjustment belongs to: CO is a contractual obligation, PR is patient responsibility, OA is other adjustment, PI is payer-initiated reduction, and CR is correction or reversal. The reason code, called a CARC, says why.

Checking a payment against your contract

For each service line, add up what the payer paid and what it assigned to the patient. That total is the amount the payer treated as allowed, although how an allowed amount is reported can vary, so confirm it against the remittance itself.

Compare that amount with the contracted rate for the same procedure code, modifier, and date of service. A difference is a reason to look closer, not proof of an underpayment: read the adjustment codes on the line first, because reductions such as multiple-procedure rules can explain it.