Glossary
Reference-year release (RY/DY lag)
Reference-year release (RY/DY lag) is CMS's annual publication convention in which a release named for its reference year (RY26 files published in 2026) carries the earlier data year (DY24), leaving roughly a one-year lag between service year and publication. In Datadory's catalog of 1,744 datasets, cms-data-hub-medicare-medicaid-datasets and cms-medicare-provider-charge-data-inpatient-outpatient are working examples.
What is Reference-year release (RY/DY lag)?
CMS's annual publication convention in which a release named for its reference year (RY26 files published in 2026) carries the earlier data year (DY24), leaving roughly a one-year lag between service year and publication.
In this catalog it appears concretely: - cms-data-hub-medicare-medicaid-datasets — "Provider-summary family covers 2013-2024 service years with annual reference-year releases (RY26 files published 2026)". - cms-medicare-provider-charge-data-inpatient-outpatient — "released annually with roughly a one-year lag (RY26 release carries DY24 data)".
cms-medicare-provider-charge-data-inpatient-outpatient is the second reference point worth knowing: "released annually with roughly a one-year lag (RY26 release carries DY24 data)". Reading the two together shows how much variation sits underneath one shared label.
Why does Reference-year release (RY/DY lag) matter when choosing a dataset?
A label on a listing is not a deliverable. Teams that license on the strength of a product-name match routinely find the shipped files cover a narrower slice than they assumed, and backfilling history afterwards costs more than the license ever did.
The failure mode is concrete: a source can carry the Reference-year release (RY/DY lag) label while differing from what you need on exactly the dimension that matters — Provider-summary family covers 2013-2024 service years with annual reference-year releases (RY26 files published 2026). Comparing two sources on that line usually settles the choice faster than any feature matrix.
You rarely have to take a vendor's word for it. 82.4% of the 1,744 datasets Datadory catalogs are free to access, and cms-data-hub-medicare-medicaid-datasets lets you inspect the real artifact before any budget is committed.
How do you evaluate Reference-year release (RY/DY lag) in a data source?
Treat every claim of this attribute as testable:
- Open cms-data-hub-medicare-medicaid-datasets and confirm its record — "Provider-summary family covers 2013-2024 service years with annual reference-year releases (RY26 files published 2026)" — against the files you actually receive.
- Open cms-medicare-provider-charge-data-inpatient-outpatient and confirm its record — "released annually with roughly a one-year lag (RY26 release carries DY24 data)" — against the files you actually receive.
See the term applied to real records: health-care-reits data, life-health-insurance data.
Related terms
Adjacent concepts worth reading next: - price transparency data
Frequently asked questions
What is an example of Reference-year release (RY/DY lag)?
cms-data-hub-medicare-medicaid-datasets is the clearest example in this catalog. Its record states: "Provider-summary family covers 2013-2024 service years with annual reference-year releases (RY26 files published 2026)". Across all 1,744 datasets Datadory averages a quality score of 7.81 out of 10, so a named example can be weighed rather than trusted blindly.
Is data described as "Reference-year release (RY/DY lag)" free to use?
Treat access and permission separately. 82.4% of the 1,744 datasets in this catalog are free to access, but 235 are freemium and 61 are paid outright, so confirm both the price and the license on the exact distribution before building on it.
How do I verify a source really provides Reference-year release (RY/DY lag)?
Open cms-data-hub-medicare-medicaid-datasets next to cms-medicare-provider-charge-data-inpatient-outpatient and compare the promise with the download. Field definitions are verified for 1495 of 1,744 datasets (85.7%), which makes that check fast inside the catalog and manual outside it.
Datasets containing this field
Datasets containing Reference-year release (RY/DY lag)
6 datasets carry reference-year release (ry/dy lag) in the catalog. Open one, count the fields, judge for yourself.
CDC Data.CDC.gov Open Data Portal
CDC NCHS Data Browsing Collection
CMS Provider Data Catalog
Dartmouth Atlas of Health Care
HCUP - Healthcare Cost and Utilization Project
Yahoo Finance Health Care REIT Quote Pages
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