> ## 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.

# Billing forms

> CMS-1500 vs UB-04, when to use each, and their EDI equivalents

Healthcare claims use two standard forms, depending on the type of service and facility.

## CMS-1500 (837P)

| Attribute                 | Value                                                       |
| ------------------------- | ----------------------------------------------------------- |
| **Paper form**            | CMS-1500                                                    |
| **Electronic equivalent** | 837P (Professional)                                         |
| **Used by**               | Physicians, clinics, ambulatory surgery centers             |
| **Service types**         | Professional services, office visits, outpatient procedures |

The CMS-1500 is the standard for **professional claims** — services performed by individual providers.

## UB-04 (837I)

| Attribute                 | Value                                                              |
| ------------------------- | ------------------------------------------------------------------ |
| **Paper form**            | UB-04                                                              |
| **Electronic equivalent** | 837I (Institutional)                                               |
| **Used by**               | Hospitals, SNFs, home health agencies, hospice                     |
| **Service types**         | Inpatient stays, outpatient hospital services, facility-based care |

The UB-04 is the standard for **institutional claims** — services provided by facilities.

## How RCI determines billing form

The L2 (Facility Type) layer resolves the correct billing form based on the facility's CCN:

| Facility Type                    | Billing Form | EDI  |
| -------------------------------- | ------------ | ---- |
| Short-term hospital (outpatient) | CMS-1500     | 837P |
| Short-term hospital (inpatient)  | UB-04        | 837I |
| Critical Access Hospital         | UB-04        | 837I |
| Home Health Agency               | UB-04        | 837I |
| Skilled Nursing Facility         | UB-04        | 837I |
| Physician office                 | CMS-1500     | 837P |

```bash theme={null}
curl -X POST https://api-dev.rcintell.com/v1/knowledge/billing-guide \
  -H "X-API-Key: kp_test_..." \
  -H "Content-Type: application/json" \
  -d '{"ccn": "170001", "cpt": "99213", "payer": "Medicare"}'
```

## Type of Bill (TOB) codes

UB-04 claims require a Type of Bill code. RCI's L2 layer resolves the primary TOB code for the facility:

| TOB | Description                                  |
| --- | -------------------------------------------- |
| 111 | Hospital inpatient (admit through discharge) |
| 131 | Hospital outpatient                          |
| 321 | Home health (RAP)                            |
| 211 | Skilled nursing (admit through discharge)    |
| 811 | Hospice (admit through discharge)            |