ERA vs EOB: what is the difference?
An ERA (electronic remittance advice) is the X12 835 file a payer sends to explain a claim payment. An EOB (explanation of benefits) is the paper or PDF statement that explains the same thing. Both show what was billed, allowed, paid, adjusted and left to the patient. Software can post an ERA directly; an EOB has to be read.
Also calledElectronic remittance advice835Explanation of benefits
By Dr. Maya Arnaout, DDS, VP of RevenuePublished 4 min read
What is an ERA in dental billing?
An ERA is the electronic version of the payer’s explanation of a payment. Its formal name is the ASC X12 835 Health Care Claim Payment/Advice, which is why billers call it “the 835”. It reaches the practice through a clearinghouse once the practice has enrolled for ERAs with that payer.
One 835 can cover many claims. It is built from segments: a payment header with the total and the method, a trace number that ties it to the deposit, then each claim, each procedure line and each adjustment with its reason code.
Dana Whitfield · Seen 09/12/2026 · Claim SAMPLE1001
| Code | Billed | Allowed | Paid | Patient | Reason |
|---|---|---|---|---|---|
| D1110 | 120.00 | 90.00 | 72.00 | 18.00 | CO-45PR-2 |
| D0120 | 65.00 | 45.00 | 45.00 | 0.00 | CO-45 |
| Total | 185.00 | 135.00 | 117.00 | 18.00 |
The same claim, as the payer’s 835 file
CLP*SAMPLE1001*1*185*117*18~Claim: billed $185, paid $117, patient owes $18SVC*AD:D1110*120*72~Adult cleaning: billed $120, paid $72CAS*CO*45*30~Write-off $30: over the fee scheduleCAS*PR*2*18~Coinsurance $18: the patient owes itSVC*AD:D0120*65*45~Periodic exam: billed $65, paid $45CAS*CO*45*20~Write-off $20: over the fee schedule
What is an EOB?
An EOB is the statement a person reads: a printed page in the mail, often with a check, or a PDF downloaded from a payer portal. Every payer lays it out differently, so someone has to find the patient, the procedure lines, the amounts and the codes on each page before anything is posted.
Patients get an EOB too. Theirs explains what the plan paid and what they may owe; it is not a bill. The practice’s version often lists many patients under one payment.
How are an ERA and an EOB different?
| Compared on | ERA (835) | EOB |
|---|---|---|
| Format | A standard electronic file, the X12 835 | A paper page or PDF, laid out by each payer |
| How it arrives | Through the clearinghouse, after ERA enrollment | By mail, or downloaded from the payer portal |
| Money that usually comes with it | An EFT deposit, matched by trace number | A paper check, or a virtual card notice |
| Reason codes | CARC, RARC and group codes in fixed fields | Printed codes or the payer’s own wording |
| How it gets posted | Imported by software; exceptions reviewed | Read and keyed line by line |
| Matching to the bank | Trace number and amount | Check number and amount |
How does each one get posted?
An ERA can be imported into the practice management system or a posting tool, which finds each claim and posts the payment, the contractual write-off and the patient’s portion. Staff still review what did not match: a claim the system cannot find, a partial payment, a denial.
An EOB is posted by hand. Someone opens the page, finds each claim in the PMS, keys the paid amount, the write-off and the patient portion for every procedure line, then scans the EOB to the account. Every line typed is a chance for a keying error.
Either way, posting is not finished until the payment is matched to the money in the bank. See remittance advice and payment reconciliation.
Why do practices still get paper EOBs?
- The practice is not enrolled for ERAs with every payer, or an enrollment lapsed after a change of tax ID, address or bank account.
- Some smaller plans and secondary payers still pay by check with a printed EOB.
- Virtual card payments often come with a PDF remittance instead of an 835.
- Payer portals hold remittances as PDFs that someone has to download.
How ScoutIQ handles it
ScoutIQ reads every ERA and paper EOB line by line, whether it comes from the clearinghouse, a payer portal, a staff upload or the ScoutIQ PO Box for paper mail. It posts paid amounts, write-offs and patient responsibility to your PMS, and 95% of insurance payments are matched to their EOB with no human review.
Insurance Billing Automation
ERAs and EOBs read; EFT, check and card payments reconciled.
See Insurance Billing Automation