Outpatient utilization · Reference

Per-CCN per-APC outpatient utilization, free + open. Sister dataset to Inpatient.

The CMS Medicare Outpatient Hospitals file is annual. Fonteum has a configured daily probe schedule, but that schedule does not prove a current load; check the endpoint's dated loaded snapshot. Published data years contain approximately 117K rows.

Try the API → Inpatient sister dataset → Data catalog →

1. What this dataset is

Per-CCN per-APC Medicare outpatient service + payment aggregates.

CMS publishes the “Medicare Outpatient Hospitals by Provider and Service” file annually each mid-June. One row per (CCN, APC code, data year). Each row carries the count of services, distinct beneficiaries served, average submitted charges, and average Medicare payment amount. Coverage extends back to data year 2018 in the current schema.

APC = Ambulatory Payment Classification (the outpatient analogue to inpatient’s MS-DRG) — it is the “service” grain of this file. Unlike the Physician & Other Practitioners file, the outpatient file carries no HCPCS column; the APC code lets payers + analysts join utilization back to service category at row level.

2. What this dataset is NOT

No PHI. No claims. No patient records.

Same suppression rules as Inpatient:

NO patient identifiers — no names, no addresses, no dates of birth.
NO claim-level rows — only annual rollups per (CCN, APC).
NO service dates — just the data year.
NO cells with service counts under 11 — CMS pre-suppresses these per its privacy policy.

Provider-name and provider-address columns dropped at parse time (CMS POS holds the canonical metadata; dual-storage would create drift).

3. Refresh schedule

Configured probe schedule: 06:00 UTC daily. Loaded freshness is reported separately.

The configured schedule matches Inpatient (0 6 * * *). A configured probe does not prove a current load or a successful run. The endpoint's dated snapshot is the freshness evidence.

4. How it joins to other sources

CCN bridges to POS, Care Compare, and the Inpatient sister table.

Same CCN bridge as Inpatient. Researchers comparing inpatient + outpatient utilization for the same facility join the two tables on (ccn, data_year). The federated identity layer at /identity documents the canonical CCN ↔ NPPES NPI ↔ ownership-chain links.

5. The API

`GET /api/v1/utilization/outpatient/[ccn]`

Returns the top-10 APCs by service count for the given CCN. Source-level provenance metadata appears where the endpoint supplies it; fields can be null and do not establish an individual-fact signature.

{
  "data": {
    "ccn": "010001",
    "data_year": 2022,
    "top_apcs": [
      {
        "apc_code": "0019",
        "apc_description": "Level 1 Excision/Biopsy/Incision",
        "total_services": 1245,
        "total_beneficiaries": 812,
        "avg_total_submitted_charges": 560,
        "avg_medicare_payment_amt": 138,
        "data_year": 2022
      }
    ],
    "provenance": {
      "_source": "CMS Medicare Outpatient Hospitals by Provider and Service",
      "_dataset_id": "cms-outpatient-utilization",
      "_snapshot": "2022-12-31",
      "_methodology": "v2026.05.0",
      "_license": "US-Government-Works",
      "_coverage_period_start": "2018-01-01",
      "_coverage_period_end": "ongoing"
    }
  },
  "meta": { "request_id": "req_...", "api_version": "v1", "...": "..." }
}

6. License + redistribution

US-Government-Works. Anyone can redistribute.

Same license posture as Inpatient — federal-government work, public domain in the U.S. under 17 U.S.C. §105 + Open Government Data Act. SPDX US-Government-Works.

7. How to cite

APA-ish, with the upstream CMS source named.

Fonteum. (2026). CMS Medicare Outpatient
Hospitals by Provider and Service [data set]. https://fonteum.com/docs/utilization-outpatient.
Retrieved [date]. Original source: Centers for Medicare & Medicaid
Services. License: US-Government-Works.

8. Verify the snapshot

SHA-256 attestation + S3 cache mirror.

Same attestation chain as Inpatient. Use /verify + /chain to walk the cryptographic chain for any snapshot.