Supplemental Data

Terms and Conditions of Data Use: please read before downloading data.

These supplemental materials are available to help researchers use Atlas regions and methods in their own work.


ZIP Code Crosswalks

Our ZIP code to HSA to HRR crosswalk files allow you to aggregate data you may have at the ZIP code level to the hospital service area (HSA) or hospital referral region (HRR) level.

Other Crosswalks

Geographic Boundary Files

Our boundary files allow you to create your own maps using ESRI® ArcGIS® software. The shape files are not projected. The geographic coordinate system is North American Datum 1983.

During each annual CMS data file update, we produce trend files of the year-to-year suppressed event and person counts of the diagnosis and procedure codes used in the Medicare claims files: MedPAR, Part B (Carrier), and Outpatient. These coding trends are useful for researchers to determine if there was a change (increase/decrease) over time that may indicate that a code is obsolete or a different code is being used to capture a particular diagnosis or procedure.

The coding trends rely on Medicare claims files. Each of the codes includes a descriptive label (except for HCPC/CPT due to AMA copyright). Each file includes a description of the codes and the Medicare file from which the data was derived, as well as a link to the data dictionary located on ResDAC’s web site.

The table below shows which files are used by default and the sample size.

TypeSource FilesSample Size
Diagnosis CodeptbYYYYclmp1
HCPCS CodeptbYYYYlnitp1
Revenue CodeopYYYYrevp120%
Procedure CodemedparYYYY100%

Note: when a 20% sample is used, the resulting code count is multiplied by five to arrive at the final count.

2004-2018 Coding Trends Files
ICD9 to ICD10

Hospital Research Data

Hospital Tracking Files
DRGs by Provider (Excel)
Cardiac Care Hospital Data (1996-2014)
Hospital Cost File (1998-2012)