# CMS Hospital Service Area (referral geography by CCN × ZIP)

`medicare_silver.fact_hospital_service_area` · Hospital price transparency · status live · 1,155,777 rows

The CMS Hospital Service Area file — for each hospital (CCN) the ZIP codes its Medicare FFS patients reside in, with total_cases, total_days_of_care, total_charges. The referral-GEOGRAPHY layer: which markets a hospital draws from, and (inverted) which hospitals serve a ZIP / compete in a market. Multi-year (2015–2024), partitioned by data_year.

**Grain.** One row per (data_year, hospital CCN, patient ZIP) — cases/days/charges.

| column | type | meaning |
|---|---|---|
| data_year | int |  |
| ccn | string |  |
| zip_code | string |  |
| total_cases | double |  |
| total_days_of_care | double |  |
| total_charges | double |  |
| observed_period | date |  |
| asserted_at | date |  |
| effective_period_start | date |  |
| effective_period_end | date |  |
| cms_vintage_sequence | int |  |
| parse_revision | int |  |
| parser_artifact_hash | string |  |
| source_url | string |  |
| sha256_content_hash | string |  |
| source_id | string |  |
| is_current | boolean |  |
| bronze_object_key | string |  |
| s3_version_id | string |  |
| vintage_tag | string |  |
| drug_source_version_id | string |  |

Query it: `query_substrate` with `SELECT ... FROM medicare_silver.fact_hospital_service_area WHERE ... LIMIT 100`; read `describe_data_source("medicare_silver.fact_hospital_service_area")` first.