> ## Documentation Index
> Fetch the complete documentation index at: https://dso.getlemma.com/llms.txt
> Use this file to discover all available pages before exploring further.
# The 835: how payers answer
> How to read a dental remittance: claim and line detail, adjustment codes, downgrades and frequency limits, PLB provider-level adjustments, and deposit reassociation.
The **835** is the X12 electronic remittance advice. It reports how the payer adjudicated claims, including payments and adjustments at the claim or service-line level. Reading it accurately is central to dental revenue operations because the same file may contain contractual adjustments, patient responsibility, claim denials, alternate benefits, and plan limitations.
## File structure
An 835 has three levels:
```mermaid theme={null}
graph TB
A["File level, BPR, TRN
total payment, method, trace number"] --> B["Claim level, CLP
per claim: charged, paid, patient responsibility, status"]
B --> C["Service line level, SVC, CAS
per procedure: charged, paid, adjustments"]
A --> D["Provider level, PLB
takebacks, interest, withholds, outside the claims"]
```
## The key segments
| Segment | Carries |
| ------- | --------------------------------------------------------------------------------------------------------- |
| **BPR** | Total payment amount, payment method (ACH, check, non-payment), effective date |
| **TRN** | **Reassociation trace number**, used to match the remittance with an EFT deposit |
| **CLP** | Claim-level: patient account number, claim status code, total charged, total paid, patient responsibility |
| **CAS** | Adjustments identified by group code, reason code, and amount; may appear at claim or line level |
| **SVC** | Service line: procedure code, charged, paid |
| **PLB** | **Provider-level adjustments**, outside any claim |
| **NM1** | Payer, payee, patient identification |
## The adjustment grammar
The core concept. Every dollar not paid is explained by a triple:
**Group code + CARC (+ optional RARC)**
### Group codes, who bears the cost
| Code | Meaning | Your action |
| ------ | ------------------------- | -------------------------------------------------------- |
| **CO** | Contractual obligation | **Write it off.** You may not bill the patient. |
| **PR** | Patient responsibility | **Bill the patient.** |
| **OA** | Other adjustment | Usually informational or a transfer to another payer |
| **PI** | Payer-initiated reduction | The payer's decision, not contractual. Often appealable. |
**Group codes affect the patient ledger.** Posting a valid PR amount as CO may suppress a patient balance, while posting a CO amount as PR may bill the patient for an amount the participation agreement requires the practice to adjust. Configure auto-posting carefully and review payer-specific exceptions.
### CARCs, why
**Claim Adjustment Reason Codes** are maintained by X12. The ones a dental biller sees constantly:
| CARC | Meaning |
| ---- | ------------------------------------------------------------------------------------------------ |
| 1 | Deductible |
| 2 | Coinsurance; the percentage depends on the product and service category |
| 3 | Copayment |
| 45 | **Charge exceeds fee arrangement or maximum allowable**, often used for a contractual adjustment |
| 16 | Claim lacks information or has a submission error |
| 18 | Duplicate claim |
| 22 | Another payer may be responsible under coordination-of-benefits rules |
| 29 | Time limit for filing has expired |
| 96 | Non-covered charge |
| 197 | Required preauthorization or notification was absent |
| 198 | Preauthorization exceeded |
| 204 | Not covered under the patient's benefit plan |
| 252 | Additional documentation is required, which may include a radiograph or narrative |
The full working set: [CARC codes](/reference/edi/carc-codes).
### RARCs, the detail
**Remittance Advice Remark Codes** add detail to a CARC. For example, a RARC paired with CARC 16 may identify the missing information. In dental remittances, a RARC may also clarify the frequency rule, documentation request, or alternate-benefit rationale. See [RARC codes](/reference/edi/rarc-codes).
## Reading a dental claim
Two lines from one visit: an adult prophy and a one-surface posterior composite the plan downgraded to the amalgam allowance.
| | Line 1 (D1110 prophy) | Line 2 (D2391 composite) |
| ---------------------- | --------------------- | ----------------------------------------- |
| Billed | \$\$142.00 | \$\$310.00 |
| Allowed | \$\$98.00 | \$\$175.00, using the *amalgam* allowance |
| Contractual write-off | \$\$44.00 | \$\$60.00 |
| Patient responsibility | \$\$0.00 | \$\$110.00 |
| **Paid** | **\$\$98.00** | **\$\$140.00** |
Line 1 is the happy path: *billed − contractual = allowed; allowed − patient share = paid*, and preventive pays at 100% of allowed.
Line 2 was paid using an **alternate-benefit allowance** rather than the office's composite charge. Under the example plan, the payer calculated the benefit as though an amalgam had been placed.1 Whether the remaining amount may be billed to the patient depends on the participation agreement, plan terms, applicable law, and pre-treatment disclosure. Payers represent these calculations differently, so review the allowed amount, group and reason codes, remarks, and EOB together. See [Denials vs downgrades](/concepts/payments/denials-vs-downgrades).
**Frequency limits and exhausted maximums** also appear as plan-benefit adjustments, often with CARC 96, 119, or 204 and a more specific RARC or EOB explanation. Confirm that the payer used the correct history, eligibility, and plan terms before accepting the result. Transfer any balance to the patient only when the contract, benefit terms, law, and financial consent permit it.
The **allowed amount** drives the contracted payment calculation. The contractual adjustment is the difference between the submitted charge and that allowance. Review the allowance and applicable fee schedule rather than treating the size of the write-off alone as a performance measure.
## PLB, the segment that breaks reconciliation
**Provider-level adjustments** sit outside the claim detail and adjust the total payment. They carry:
| PLB reason | What it is |
| ---------- | ---------------------------------------------------------------- |
| **WO** | Overpayment recovery, including a takeback against a prior claim |
| **FB** | Forwarding balance, carried to a future remittance |
| **L6** | Interest owed to you for late payment |
| **CS** | Adjustment |
| **72** | Authorized return |
**PLB takebacks are recoupments, and they're how a payer recovers an overpayment without asking.** The dollars vanish from a deposit with no corresponding claim-level entry. If your posting process ignores PLB, your books overstate revenue and your reconciliation never ties. See [Handle recoupments](/guides/compliance/handle-recoupments).
## One 835 is not one bank deposit
This is an important operational feature of remittances.
* One deposit can cover **multiple** 835s
* One 835 can be split across **multiple** deposits
* The **PLB** shifts the total away from the sum of the claims
* Paper checks and virtual credit cards arrive on entirely different timelines than the 835
The mechanism for matching them is the **TRN reassociation trace number**, carried in the 835 and referenced in the ACH addenda record of the corresponding EFT.
**Reconcile by TRN, never by hunting for matching dollar amounts.** Amount-matching works until you have two payers sending similar amounts on the same day, then it produces silently wrong postings. See [Reconcile payments daily](/guides/payments/reconcile-daily-payments).
## Claim status codes (CLP02)
| Code | Meaning |
| ---- | --------------------------------------------------------------------------------- |
| 1 | Processed as primary |
| 2 | Processed as secondary |
| 3 | Processed as tertiary |
| 4 | **Denied** |
| 19 | Processed as primary, forwarded to another payer |
| 22 | Reversal of a previous payment |
| 25 | **Predetermination response**, which provides pricing information without payment |
Status 4 indicates denial, status 22 indicates reversal of a prior adjudication, and status 25 identifies a predetermination response. Configure status 25 as an estimate or benefit response rather than a zero-pay claim denial.
## Paper EOBs
An **explanation of benefits** presents similar adjudication information in a human-readable format. When ERA is available, it can reduce manual entry and support more consistent adjustment posting. An EOB from an unfamiliar payer that applies a network discount may require a [network-leasing](/concepts/payments/network-leasing) trace rather than only a posting correction.
## Why 835s are PHI
An 835 contains patient names, member IDs, dates of service, and procedure detail. It is protected health information in every sense.
Treat it accordingly: encrypted in transit and at rest, access-controlled, covered by BAAs wherever it lands, including any analytics warehouse you build. And **never put PHI in a bank memo field** when reconciling. See [HIPAA fundamentals](/concepts/compliance/hipaa-fundamentals).
## Sources
1. ADA, [Least expensive alternative treatment (LEAT) clause](https://www.ada.org/resources/practice/dental-insurance/least-expensive-alternative-treatment-clause).