What is the 'allowed amount' on a dental EOB?

The allowed amount is the maximum the plan recognizes for a procedure — the contracted fee for in-network providers. The plan pays its share of the allowed amount; the patient owes any deductible, coinsurance, or copay; and the difference between your billed charge and the allowed amount is a contractual write-off for in-network claims.

How do I spot an underpayment on an EOB?

Compare the plan-paid amount plus legitimate patient responsibility to the allowed (contracted) amount for the procedure. If the total falls short of the contracted rate — with no valid reason — the claim was underpaid. Also watch for a procedure paid at a lower code (downcoding) than the one submitted.

How to Read a Dental EOB / ERA: A Field-by-Field Guide (2026)

Q: What is the difference between an EOB and an ERA?

An EOB (Explanation of Benefits) is the human-readable statement showing how a claim was processed. An ERA (Electronic Remittance Advice), delivered as the X12 835 transaction, is the electronic, machine-readable version that posts automatically to the practice-management system. They carry the same information — billed, allowed, paid, patient responsibility, and the adjustment (CARC/RARC) codes.

Every denial and every underpayment is spelled out on the remittance — if you know which fields to read and which codes to trust.

The EOB (Explanation of Benefits) is the payer's account of what it did with a claim. Its electronic twin, the ERA — delivered as the X12 835 transaction — carries the same information and posts automatically to your practice-management system. Learn to read the columns and you can spot a denial or an underpayment in seconds.

The fields that matter

Field	What it is
Billed / Submitted	The fee you charged for the procedure.
Allowed	The maximum the plan recognizes — your contracted fee, in-network. Everything else keys off this number.
Plan paid	The plan's share of the allowed amount, after patient responsibility.
Deductible / Coinsurance / Copay	The patient's share (CARC PR-1 / PR-2 / PR-3).
Contractual write-off	Billed minus allowed, for in-network claims (CARC CO-45). Not billable to the patient.
Adjustment codes	The CARC (reason) and RARC (remark) codes explaining any reduction or denial.
Patient responsibility	What you may bill the patient — deductible, coinsurance, copay, and non-covered amounts only.

The arithmetic is simple and always holds: Billed = Plan paid + Patient responsibility + Contractual write-off + any denied amount. When those don't reconcile to your contracted allowed amount, something is off.

How to spot a denial

A denial is a line where the plan paid zero and a CARC explains why. Read the group code first (CO, PR, OA, PI), then the reason: CO-197 (authorization absent), CO-29 (timely filing), CO-18 (duplicate), CO-16 (missing info — check the RARC). Our denial-codes reference covers each.

How to spot an underpayment

Underpayments hide in "paid" claims. Compare plan paid + legitimate patient responsibility against the allowed (contracted) amount. A shortfall with no valid reason is money owed. Also watch for a procedure paid at a lower code than you submitted — that's downcoding. And watch the group code on reason 45: as PR-45 on an in-network claim, it's a balance-billing red flag.

ClaimZen reads every EOB and 835 the way this guide describes — reconciling paid against contracted, checking each code against your own records, and flagging the denials and underpayments worth appealing. Nothing is sent without your approval.

Frequently asked questions

What is the difference between an EOB and an ERA?

An EOB is the human-readable statement; an ERA (the X12 835) is the electronic version that auto-posts. Same information — billed, allowed, paid, patient responsibility, and the CARC/RARC codes.

What is the "allowed amount"?

The maximum the plan recognizes for a procedure — your contracted fee, in-network. The plan pays its share of it; the patient owes cost-sharing; the rest is a contractual write-off.

How do I spot an underpayment?

Compare plan paid plus legitimate patient responsibility to the allowed amount. A shortfall with no valid reason is an underpayment. Watch for downcoding too.

Sources

X12, Claim Adjustment Reason Codes and the 835 Health Care Claim Payment/Advice transaction.

General information, not billing, legal, or coding advice. EOB layouts vary by payer.

How to read a dental EOB (and the ERA behind it)