Terms and Conditions of Data Use: please read before downloading data.
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.
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 unsuppressed 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useful for researchers to determine if there was a change (increase/decrease) over time that may indicate that a code is obsolete or a different code is being used to capture a particular diagnosis or procedure.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. 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.
Note: when a 20% sample is used, the resulting code count is multiplied by five to arrive at the final count.
Longitudinal research files
These files are intended to make our database easier to use for researchers conducting longitudinal studies. They include data for multiple years for each measure, most going back at least as far as 2008, allowing researchers to access several years' worth of Dartmouth Atlas rate data. In addition to adjusted rates, the files contain crude rates, numerators, denominators, 95% confidence limits, and standard errors. They are available in STATA (.dta) and Microsoft Access (.mdb) format to allow investigators to use the software of their choice to run analyses. Data are available for states, hospital referral regions, hospital service areas, counties, and individual hospitals.