> ## Documentation Index
> Fetch the complete documentation index at: https://mso.getlemma.com/llms.txt
> Use this file to discover all available pages before exploring further.

# The 835: how payers answer

> The remittance mental model: claim and line detail, the adjustment grammar, PLB provider-level adjustments, and why one 835 is not one bank deposit.

The **835** is the X12 electronic remittance advice: the payer's line-by-line explanation of what it did with your claims and why. Every dollar of difference between what you billed and what you received is accounted for in it. Reading one fluently is the most valuable skill in healthcare revenue operations.

## The mental model

An 835 has three levels:

```mermaid theme={null}
graph TB
    A["File level, BPR, TRN<br/>total payment, method, trace number"] --> B["Claim level, CLP<br/>per claim: charged, paid, patient responsibility, status"]
    B --> C["Service line level, SVC, CAS<br/>per procedure: charged, paid, adjustments"]
    A --> D["Provider level, PLB<br/>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**, how you match this remittance to the deposit                              |
| **CLP** | Claim-level: patient account number, claim status code, total charged, total paid, patient responsibility |
| **CAS** | Adjustments, group code, reason code, amount. Appears at both claim and line level.                       |
| **SVC** | Service line: procedure code, charged, paid, allowed units                                                |
| **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 drive your patient ledger.** Posting a PR amount as CO means you never bill a patient who owes you money, pure revenue loss. Posting a CO amount as PR means you bill a patient for something your contract says they don't owe, which is a balance-billing problem, not just an error.

### CARCs, why

**Claim Adjustment Reason Codes** are maintained by X12. The ones you'll see constantly:

| CARC | Meaning                                                                |
| ---- | ---------------------------------------------------------------------- |
| 1    | Deductible                                                             |
| 2    | Coinsurance                                                            |
| 3    | Copayment                                                              |
| 45   | **Charge exceeds fee arrangement**, the standard contractual write-off |
| 16   | Claim lacks information or has a submission error                      |
| 18   | Duplicate claim                                                        |
| 22   | Coverage by another payer (coordination of benefits)                   |
| 29   | Time limit for filing has expired                                      |
| 96   | Non-covered charge                                                     |
| 97   | Payment included in another service's allowance (bundled)              |
| 197  | Precertification/authorization absent                                  |
| 204  | Not covered under the patient's benefit plan                           |

The full working set: [CARC codes](/reference/edi/carc-codes).

### RARCs, the detail

**Remittance Advice Remark Codes** qualify a CARC when it alone is ambiguous. A CARC 16 with a RARC telling you *which* information is missing is actionable; a bare CARC 16 is a scavenger hunt. See [RARC codes](/reference/edi/rarc-codes).

## Reading a claim

|                   | Line 1       | Line 2      |
| ----------------- | ------------ | ----------- |
| Billed            | \$285.00     | \$195.00    |
| Allowed           | \$148.32     | \$121.45    |
| CO-45 contractual | \$136.68     | \$73.55     |
| PR-2 coinsurance  | \$29.66      | \$24.29     |
| **Paid**          | **\$118.66** | **\$97.16** |

Reading it: *billed − contractual = allowed; allowed − patient responsibility = paid.*

The **allowed amount** is the real number. Your billed charge is a chargemaster rate no contracted payer pays; the contractual adjustment is the arithmetic difference. New operators fixate on the write-off column, which is the least informative number on the page.

## 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, 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                                      |

<Warning>
  **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 and takebacks](/guides/compliance/handle-recoupments).
</Warning>

## One 835 is not one bank deposit

The single most important operational fact about 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.

<Tip>
  **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).
</Tip>

## 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, pricing only, no payment       |

Status 4 sends the line to the denial queue. Status 22 is a reversal, and it means a claim you already posted as paid is being unwound.

## Paper EOBs

An **explanation of benefits** is the paper equivalent. Same information, unstructured, requiring manual posting. Every paper EOB is a payer you should push to ERA, both for the labor saving and because manual posting is where group-code errors happen.

## Why 835s are PHI

An 835 contains patient names, member IDs, dates of service, diagnosis and procedure information, and amounts. 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 for MSO-PC operators](/concepts/compliance/hipaa-fundamentals).


## Related topics

- [Step 11: Read your first 835 and get paid](/start/zero-to-paid/read-your-first-835.md)
- [Post payments from 835s](/guides/billing/post-payments-from-835s.md)
- [Reconcile payments daily](/guides/payments/reconcile-daily-payments.md)
- [Claim denials, explained](/concepts/payments/claim-denials.md)
- [EDI and X12, gently](/concepts/payments/edi-and-x12-basics.md)
- [835 file anatomy](/reference/edi/835-anatomy.md)
- [CARC codes (Claim Adjustment Reason Codes)](/reference/edi/carc-codes.md)
- [Group codes (CO, PR, OA, PI)](/reference/edi/group-codes.md)