GET /datastore/query/{dataset_id}/{index}

cms.gov:cms-provider-data-api

Summary: Query dataset
Operation ID: queryDataset
Auth: none

Queries actual data records from a specific dataset. This is the primary endpoint for accessing healthcare data. You provide a dataset ID (like '23ew-n7w9' for dialysis facilities) and an index (typically 0), and receive structured records matching that dataset's schema. Supports pagination with limit/offset parameters. Returns facility information, quality measures, contact details, and performance metrics depending on which dataset you query.

Original spec description

Query data from a specific CMS dataset.

Usage Tips

- The `index` parameter is typically 0 for the primary resource in a dataset - Default limit is 500 records; use pagination for large datasets - Results follow the dataset's specific schema - each dataset returns different fields - Response includes `results` array and `count` total matching records

Parameters (4)

dataset_id (string, path, required)

Dataset identifier (e.g., 23ew-n7w9)

index (integer, path, required, default: 0)

Index number (typically 0)

limit (integer, query, optional, default: 100)

Maximum number of records to return

offset (integer, query, optional, default: 0)

Offset for pagination

Examples (3)

TitleTypeURLAction
Query dataset with default limit curl https://data.cms.gov/provider-data/api/1/datastore/query/23ew-n7w9/0
Query dataset with custom limit curl https://data.cms.gov/provider-data/api/1/datastore/query/4pq5-n9py2/0?limit=50
Query dataset with pagination offset curl https://data.cms.gov/provider-data/api/1/datastore/query/b27b-2br7/0?limit=25&offset=100

Probe History

Latency

Status Codes

TimeStatusLatencySize
2026-03-23 10:11:59.820672 200 4439ms 2.0MB
2026-03-23 10:10:26.840494 404 292ms
2026-03-23 09:01:44.535691 404 349ms

Response Changes

WhenOldNew
2026-03-23 10:10:26.840494 f06b917cf094 0148eaf9526c
2026-03-23 10:11:59.820672 0148eaf9526c 3226a1f10e78