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

# Denial Code Inspector

> Paste CARC/RARC codes, get plain-English interpretation and appeal strategies

> Paste a denial code. Get the explanation and what to do next. Free.

The Denial Code Inspector is RCI's public tool for interpreting claim denial codes. Enter CARC and RARC codes from an ERA — get a plain-English explanation, the common root cause, and an actionable appeal strategy.

**Try it at [rcintell.com/tools](https://rcintell.com/tools)**

## How it works

Enter:

* **CARC** — Claim Adjustment Reason Code (e.g., `197`)
* **RARC** — Remittance Advice Remark Code (e.g., `N479`)
* **Payer** (optional) — for payer-specific appeal rules

Get:

```
CARC 197: Precertification/authorization/notification absent

RARC N479: Missing prior authorization

Category: Prior Authorization
Frequency: Common (top 10 denial reason)

Root Cause:
  The procedure was performed without obtaining prior
  authorization from the payer.

Action Plan:
  1. Check if retro-authorization is available for this payer
  2. Gather clinical documentation supporting medical necessity
  3. Submit retro-auth request if available
  4. If denied, file formal appeal with:
     - Letter of medical necessity
     - Clinical notes supporting the procedure
     - NCD/LCD reference if applicable

Payer-Specific (Medicare):
  Appeal Level: Redetermination
  Deadline: 120 days from denial date
  Where to file: MAC Jurisdiction 5

Payer-Specific (Commercial):
  Appeal Level: Internal appeal
  Deadline: 180 days (varies by plan)
  Where to file: Payer appeals department
```

## Common denial codes

| CARC | Description                                            | Category               | Frequency   |
| ---- | ------------------------------------------------------ | ---------------------- | ----------- |
| 1    | Deductible                                             | Patient responsibility | Very common |
| 2    | Coinsurance                                            | Patient responsibility | Very common |
| 3    | Copay                                                  | Patient responsibility | Very common |
| 4    | Procedure inconsistent with modifier                   | Coding                 | Common      |
| 16   | Missing/incomplete information                         | Data quality           | Very common |
| 18   | Duplicate claim                                        | Submission             | Common      |
| 29   | Filing limit expired                                   | Timeliness             | Common      |
| 50   | Non-covered service                                    | Coverage               | Common      |
| 96   | Non-covered charge                                     | Coverage               | Common      |
| 97   | Payment adjusted: benefit for this service max reached | Coverage               | Common      |
| 197  | Prior auth absent                                      | Authorization          | Very common |
| 204  | Service/equipment/drug not covered under plan          | Coverage               | Common      |

## Features

* **CARC + RARC combination** — interpret both codes together for full context
* **Payer-specific appeal rules** — select the payer for deadline and process details
* **Appeal letter template** — generate a starting point for the appeal letter
* **Bulk mode** — paste multiple denials from an 835 ERA
* **Share link** — share a specific interpretation with your team
* **History** — track your lookups (logged in users)

## API equivalent

For programmatic denial analysis with AI-powered appeal strategies:

```bash theme={null}
curl -X POST https://api-dev.rcintell.com/v1/agents/denial-resolution \
  -H "X-API-Key: kp_test_..." \
  -H "Content-Type: application/json" \
  -d '{
    "query": "Claim denied for prior auth",
    "carc": "197",
    "rarc": "N479"
  }'
```

## Free to use

The Denial Code Inspector is free at [rcintell.com/tools](https://rcintell.com/tools). No account required. AI-powered appeal strategies via the API require a free API key.