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MUE Data API

Complete API reference for querying CMS Medically Unlikely Edits (MUE) data.

Overview

The MUE Data API provides read-only access to Medically Unlikely Edits, which define the maximum units of service that a provider would report under most circumstances for a single beneficiary on the same date of service.

Base Path: /api/v1/mue-data

Authentication: Required for all endpoints (Bearer token or API Key)

MUE Types

The following MUE types are supported:

Type Description
Facility For hospital outpatient services and ASCs
Practitioner For physician and other practitioner services
DME For Durable Medical Equipment suppliers

Endpoints

Search MUE Data

Search and filter MUE records with pagination.

Endpoint: GET /mue-data/search

Query Parameters:

Parameter Type Required Description
code string No Filter by HCPCS/CPT code (prefix match)
mue_type string No Filter by type (Facility, Practitioner, DME)
effective_date string No Filter records active on date (YYYYMMDD or YYYY-MM-DD)
skip integer No Number of records to skip (default: 0)
limit integer No Maximum records to return (default: 50, max: 500)

Response:

{
  "data": [
    {
      "id": 12345,
      "code": "99213",
      "mue_type": "Practitioner",
      "mue_value": 3,
      "mue_adjudication_indicator": "1",
      "mue_rationale": "CMS Policy",
      "effective_date": 20250101,
      "end_date": 20250331,
      "record_hash": "abc123hash..."
    }
  ],
  "count": 150
}

Example Requests:

# Search for code 99213
curl -H "Authorization: API_KEY" \
  "https://api.example.com/api/v1/mue-data/search?code=99213"

# Get Facility MUEs active on Jan 1, 2025
curl -H "Authorization: API_KEY" \
  "https://api.example.com/api/v1/mue-data/search?mue_type=Facility&effective_date=20250101"

Use Cases: - Bulk data retrieval: Export MUE data for internal systems - Broad searches: Find all codes starting with a specific prefix (e.g., "99")

Get MUE by Code

Retrieve all MUE records for a specific code, optionally filtered by type and date.

Endpoint: GET /mue-data/code/{code}

Path Parameters:

Parameter Type Required Description
code string Yes HCPCS/CPT code (exact match)

Query Parameters:

Parameter Type Required Description
mue_type string No Filter by type (Facility, Practitioner, DME)
effective_date string No Filter records active on date

Response:

{
  "code": "99213",
  "records": [
    {
      "id": 12345,
      "code": "99213",
      "mue_type": "Practitioner",
      "mue_value": 3,
      "mue_adjudication_indicator": "1",
      "effective_date": 20250101,
      "end_date": 20250331
      // ... other fields
    },
    {
      "id": 12346,
      "code": "99213",
      "mue_type": "Facility",
      "mue_value": 1,
      "mue_adjudication_indicator": "2",
      "effective_date": 20250101,
      "end_date": 20250331
      // ... other fields
    }
  ],
  "count": 2
}

Example Request:

curl -H "Authorization: API_KEY..." \
  "https://api.example.com/api/v1/mue-data/code/99213"

Use Cases: - Claim validation: Check limits for a specific procedure before billing - Comparison: Compare Facility vs Practitioner limits for the same code

Get MUE by ID

Retrieve a single MUE record by its unique database ID.

Endpoint: GET /mue-data/{mue_id}

Path Parameters:

Parameter Type Required Description
mue_id integer Yes Unique record ID

Response:

{
  "id": 12345,
  "code": "99213",
  "mue_type": "Practitioner",
  "mue_value": 3,
  "mue_adjudication_indicator": "1",
  "mue_rationale": "CMS Policy",
  "effective_date": 20250101,
  "end_date": 20250331,
  "record_hash": "abc123hash...",
  "created_at": "2025-01-01T00:00:00Z",
  "updated_at": "2025-01-01T00:00:00Z"
}

Example Request:

curl -H "Authorization: API_KEY..." \
  "https://api.example.com/api/v1/mue-data/12345"

Get MUE Statistics

Get summary statistics about the MUE database coverage.

Endpoint: GET /mue-data/stats/summary

Response:

{
  "stats": {
    "Facility": {
      "total_records": 150000,
      "distinct_codes": 12000,
      "min_effective_date": 20150101,
      "max_end_date": 20251231
    },
    "Practitioner": {
      "total_records": 180000,
      "distinct_codes": 15000,
      "min_effective_date": 20150101,
      "max_end_date": 20251231
    },
    "DME": {
      "total_records": 50000,
      "distinct_codes": 4000,
      "min_effective_date": 20150101,
      "max_end_date": 20251231
    }
  }
}

Example Request:

curl -H "Authorization: API_KEY..." \
  "https://api.example.com/api/v1/mue-data/stats/summary"

Use Cases: - Health check: Verify data is loaded and up-to-date - Coverage analysis: Understand the scope of available data

Common Patterns

Date Handling

Dates are returned as integers in YYYYMMDD format (e.g., 20250101). When filtering via effective_date query parameter, you can use either: - YYYYMMDD (e.g., 20250101) - YYYY-MM-DD (e.g., 2025-01-01)

MAI Codes (Adjudication Indicators)

The mue_adjudication_indicator field determines how the edit is applied:

Code Meaning Application
1 Line Item Edit Applied to each line item individually.
2 Date of Service Edit (Policy) Applied to the sum of units for the code on the same date of service. Based on policy.
3 Date of Service Edit (Clinical) Applied to the sum of units for the code on the same date of service. Based on clinical benchmarks.

Error Handling

Status Code Description
200 Success
400 Invalid parameters (e.g., invalid mue_type or date format)
401 Unauthorized (missing/invalid token)
404 Record not found
500 Server error