Welcome to the CMS Chronic Condition Data Warehouse!

The CMS Chronic Condition Data Warehouse (CCW) provides researchers with Medicare beneficiary, claims, and assessment data linked by beneficiary across the continuum of care. In the past, researchers analyzing Medicare data files were required to perform extensive analysis related to beneficiary matching, deduplication, and merging of the files in preparation for their study analysis. With the CCW data, this preliminary linkage work is already accomplished and delivered as part of the data files sent to researchers.