> ## 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.
# Your first downgrade, and your first denial
> A worked example showing how to distinguish an alternate-benefit downgrade from a correctable dental claim denial and route each one appropriately.
Not every adverse line on a dental 835 is a denial. A **downgrade** applies an alternate-benefit provision and prices the service using a less expensive covered treatment. A **true denial** reports that the payer did not pay the service for a stated reason. The response depends on the remittance, plan terms, participation agreement, and claim facts. This tutorial works through one example of each.
## What arrived, line one: the downgrade
Bluebird's first adverse line involved a posterior composite, a white filling on a molar billed as **D2391**:
```text theme={null}
Line 2: D2391 (resin-based composite, one surface, posterior)
Billed: $185.00
Allowed: $98.00 (priced at the amalgam allowance)
Paid (80%): $78.40
Patient responsibility: $63.60
Remark: benefit determined per the plan's alternate benefit provision
```
Sam initially wanted to appeal because the plan did not pay based on the filling Dr. Okafor placed. The remittance needs a closer look before anyone treats it as a denial.
The plan has a **least expensive alternative treatment (LEAT)** clause, also called an alternate-benefit provision. When two treatments are clinically accepted, the plan may calculate its benefit using the less expensive one. A posterior composite may be priced at the amalgam allowance, while a porcelain crown may be priced at the all-metal allowance.1 In this example, the payer adjudicated the submitted service under that provision. Confirm that the provision was applied correctly before deciding whether to appeal or bill the patient.
### Who owes the difference
Start with the arithmetic. In this example, Bluebird's contracted fee for D2391 is \$\$142:
| Amount | What it is |
| ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| \$\$185.00 | Bluebird's full fee |
| \$\$43.00 | Difference between the full fee and contracted fee; generally a contractual adjustment under the participation agreement |
| \$\$98.00 | The plan's allowance for the *alternate* treatment (amalgam) |
| \$\$78.40 | Plan pays 80% of the alternate allowance |
| \$\$63.60 | **Patient responsibility**: their 20% coinsurance on $98, plus the $44 difference between the amalgam allowance and the contracted composite fee |
Whether the practice may bill the downgrade difference depends on the participation agreement, plan terms, and applicable notice rules. Record the answer for that plan and confirm it again when the contract changes.1
### How to process it
1. **Post the contractual adjustment and any patient responsibility separately.** In this example, the contractual write-off is \$\$43 rather than the entire difference between the full fee and payer payment.
2. **Bill only the permitted patient amount.** Use a statement description that matches the estimate and prior patient communication.
3. **Update the estimate configuration.** Record the plan's downgrade behavior in the PMS. ADA guidance recommends explaining before treatment when LEAT may apply.1
4. **Appeal only if the facts support it.** If the payer applied the plan provision correctly, classify the line as a downgrade rather than a denial.
Downgrades, frequency limits, and exhausted annual maximums are benefit-design outcomes. Confirm how the remittance and participation agreement allocate the amount before transferring it to the patient or writing it off. See [Denials vs downgrades](/concepts/payments/denials-vs-downgrades).
## What arrived, line two: the true denial
Two weeks later, a crown claim came back at zero:
```text theme={null}
Claim: D2740 (crown, porcelain/ceramic)
Billed: $1,150.00
Allowed: $0.00
Paid: $0.00
Adjustment: CO-252 $1,150.00
```
**CARC 252** reports that the payer needs documentation it does not have. For a crown, the required material may include a pre-operative radiograph and a narrative supporting clinical need.2 The **CO** group code classifies the adjustment as a contractual obligation rather than patient responsibility. In this example, Bluebird submitted the claim without the required attachment.
This one *is* an error, and it is fixable.
### Step 1: read the whole line
| Field | Bluebird's claim |
| -------------------- | ----------------------------------------------------------- |
| Group code / CARC | CO-252, documentation required |
| RARC | Identifies what's missing; here, radiographic documentation |
| Claim status (CLP02) | 4, denied |
| Date of service | 19 days ago |
| Payer | MetLife |
| Amount at risk | \$\$1,150.00 |
| Resubmission window | Per contract, and the timely filing clock is still running |
### Step 2: root-cause it
1. **Was the attachment required?** Check the payer's documentation policy for D2740. In this example, the policy required it.
2. **Did we have it?** The radiograph existed in the imaging system. It was never attached.
3. **Why not?** The payer had not yet been added to Bluebird's attachment-requirements table. The team therefore updated both the claim and the process.
### Step 3: fix and resubmit
Upload the radiograph and narrative through the payer's required attachment workflow. That may be a service that issues a reference number carried on the claim, such as the NEA-number workflow, or the clearinghouse's integrated attachment tool. Then follow the payer's corrected-claim or reconsideration instructions and reference the original claim where required. See [Dental attachments](/reference/edi/dental-attachments).
If MetLife had denied the crown despite proper documentation, such as through a clinical-necessity determination Dr. Okafor disputed, Bluebird would file a formal appeal with the clinical record and policy citation. See [File appeals](/guides/billing/file-appeals).
Do not automatically submit an adjudicated claim again as a new original. Follow the payer's corrected-claim, reconsideration, or appeal instructions and include the original claim-control number when required. A second original may be rejected or denied as a duplicate.
### Step 4: close the prevention loop
Bluebird made two changes that week. It added MetLife to the per-payer attachment table and configured the scrubber to stop D27xx claims without an attachment reference. The automated edit protects the workflow even when the usual biller is unavailable.
## The triage question, generalized
Every adverse 835 line gets sorted with one question: **is this the plan working as designed, or is this an error?**
| What you're looking at | Family | Response |
| ----------------------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------ |
| Paid at a cheaper procedure's allowance | Downgrade / LEAT | Post correctly, bill patient the permitted difference, fix estimates |
| Reduced or zeroed; service too soon (prophy, bitewings, SRP interval) | Frequency limit | Benefit design; patient responsibility if disclosed; fix verification capture |
| Zeroed; annual maximum reached (typical CARC 119) | Exhausted maximum | Benefit design; bill the patient; the maximum should have been in the estimate |
| Denied for missing radiograph, perio chart, narrative (typical CARC 252, 16) | Documentation | Supply the documentation and follow the payer's correction or reconsideration process |
| Denied; preauthorization absent (typical CARC 197, 198) | Preauthorization | Common in Medicaid and DHMO workflows; check retro-authorization options and correct the process |
| Denied; replacement of tooth extracted before coverage began | Missing tooth clause | Benefit design; should have surfaced at verification |
| Denied; eligibility, COB, timely filing, enrollment (26/27, 22/23, 29, 8/185) | Process errors | Each has a play; see the [denial code playbook](/reference/edi/denial-code-playbook) |
Track the categories separately. Downgrades and benefit-design reductions inform estimates and patient communication. True denials feed the correction, appeal, and prevention workflow.
## Operating checks
* Every adverse line triaged as benefit-design or error within days of the 835
* Downgrade differences billed to patients, not written off, and never balance-billed where the contract forbids it
* Every true denial owned, root-cause-tagged, and untouched no longer than 14 days
* Plan-level downgrade and frequency behavior recorded where the estimate engine reads it
* Recurring root causes assigned a specific prevention action
## Next
Detect, verify, issue, and record a patient refund.
## Sources
1. ADA, [Least expensive alternative treatment (LEAT) clause](https://www.ada.org/resources/practice/dental-insurance/least-expensive-alternative-treatment-clause), including the recommendation to inform patients before treatment when LEAT may apply. Whether the difference is billable in network is set by each participation agreement.
2. Claim Adjustment Reason Codes are maintained by X12. Authoritative list: [x12.org/codes/claim-adjustment-reason-codes](https://x12.org/codes/claim-adjustment-reason-codes).