The 835 Transaction — Electronic Remittance / Payment Advice

X12 835 — Health Care Claim Payment/Advice#

The 835 is the HIPAA-mandated X12 EDI transaction set used by payers to send the electronic remittance advice (ERA) and payment details to providers. It is the structured counterpart to a paper EOB/remittance.

What the 835 contains, per claim and per service line:

• The claim and service-line identifiers tying it back to the original 837 submission.
• The billed (submitted) charge for each service line.
• The allowed amount the payer recognized.
• The paid amount.
• Claim Adjustment Reason Codes (CARC) with their Group Codes (CO, PR, OA, PI) explaining each adjustment.
• Remittance Advice Remark Codes (RARC) supplying additional detail.
• Patient-responsibility amounts (deductible, coinsurance, copay).
• Payment information that reconciles to the actual deposit, often paired with electronic funds transfer (EFT) and a reassociation trace number (the EFT/835 reassociation, using the TRN segment) so the deposit can be matched to the remittance.

Why the 835 is central to RCM automation: because the data is structured and standardized, software can auto-post payments to patient accounts, auto-identify denials and underpayments by reading the CARC/RARC/Group-code combinations, calculate contractual adjustments (e.g., CO-45 write-offs), and route exceptions into work queues. Without the 835, payment posting is a manual, error-prone keying exercise. Reading the 835 accurately — and reconciling it to the EFT deposit — is the backbone of cash posting and denial detection in revenue cycle management.