> ## 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.

# Payment systems

> OPPS, MPFS, IPPS, and other Medicare payment systems explained

Medicare uses different payment systems depending on the type of facility and setting. The L2 (Facility Type) layer in RCI determines which payment system applies.

## Payment systems

### MPFS — Medicare Physician Fee Schedule

| Attribute          | Value                                            |
| ------------------ | ------------------------------------------------ |
| **Applies to**     | Professional services (physician office, clinic) |
| **Payment method** | RVU × GPCI × Conversion Factor                   |
| **Billing form**   | CMS-1500 / 837P                                  |

MPFS is the most common payment system. Payment is calculated using Relative Value Units (RVUs) adjusted by Geographic Practice Cost Indices (GPCIs) and multiplied by the annual conversion factor.

### OPPS — Outpatient Prospective Payment System

| Attribute          | Value                                         |
| ------------------ | --------------------------------------------- |
| **Applies to**     | Hospital outpatient services                  |
| **Payment method** | Ambulatory Payment Classification (APC) based |
| **Billing form**   | UB-04 / 837I                                  |

OPPS groups outpatient services into APCs with set payment rates. Separate payment for drugs, devices, and pass-through items.

### IPPS — Inpatient Prospective Payment System

| Attribute          | Value                               |
| ------------------ | ----------------------------------- |
| **Applies to**     | Acute care hospital inpatient stays |
| **Payment method** | Diagnosis Related Group (DRG) based |
| **Billing form**   | UB-04 / 837I                        |

IPPS pays a fixed amount per inpatient discharge based on the DRG, adjusted for hospital characteristics (teaching, DSH, outliers).

### Other payment systems

| System      | Applies To                             |
| ----------- | -------------------------------------- |
| **HH PPS**  | Home health episodes                   |
| **SNF PPS** | Skilled nursing facility stays         |
| **IRF PPS** | Inpatient rehabilitation facilities    |
| **Hospice** | Hospice care (per diem rates)          |
| **CAH**     | Critical Access Hospitals (cost-based) |

## RCI and payment systems

RCI determines the applicable payment system from the facility's CCN:

```bash theme={null}
curl https://api-dev.rcintell.com/v1/knowledge/layers/170001/l2 \
  -H "X-API-Key: kp_test_..."
```

Response includes:

```json theme={null}
{
  "layer": "l2_facility_type",
  "facility_type": "Short-term Hospital",
  "payment_systems": {
    "outpatient": "OPPS",
    "professional": "MPFS",
    "inpatient": "IPPS"
  },
  "billing_form": "CMS-1500 / 837P"
}
```