How to read an 835 file (ERA) — segment by segment
The 835 is the HIPAA standard electronic remittance advice (ERA). It tells a provider what a payer paid, adjusted or denied, claim by claim. It's plain text: segments end with a terminator (usually ~), and elements inside a segment are separated by a delimiter (usually *). The ISA header at the very start defines both.
The structure
- ISA / IEA — interchange envelope: sender, receiver, date, control number, test or production.
- GS / GE — functional group;
HPmeans health care claim payment (835). - ST / SE — one transaction set = usually one payment.
The payment
- BPR — the money: BPR02 amount, BPR03 credit or debit, BPR04 method (ACH, CHK, NON for no payment), and the payment date.
- TRN — the trace number: the check number or EFT trace you'll see on the bank deposit.
- N1*PR / N1*PE — payer and payee (with the payee NPI or tax ID).
The claims
- CLP — one claim: your patient control number, status (1 primary, 2 secondary, 4 denied, 22 reversal…), billed, paid, patient responsibility and the payer's claim number.
- CAS — adjustments: a group code (CO, PR, OA, PI) and one or more reason code + amount pairs. See group codes and the CARC list.
- NM1*QC — the patient; NM1*IL the insured; NM1*82 the rendering provider.
- MOA / MIA — claim-level remark codes (RARC).
The service lines
- SVC — procedure (e.g.
HC:99213:25), billed, paid, units. - DTM*472 — date of service; CAS line adjustments; AMT*B6 allowed amount; LQ*HE remark codes.
Provider-level adjustments
PLB adjusts the whole payment rather than a claim: recoupments (WO), interest (L6), forward balances (FB) and more. See PLB codes explained.
The math that must hold
Line: billed − adjustments = paid. Claim: billed − all adjustments = paid. Payment: claims paid − PLB = BPR02. Remitgrid's free 835 viewer checks all three.
Last reviewed 2026-10-27. Code lists and payer policies change — confirm with X12 (x12.org/codes), the payer and your clearinghouse. Not billing, coding or legal advice.