SEER-CAHPS: Geographic Area Data

Census Tract and ZIP Code Measures

NCI has compiled area-level measures from existing data sources at the ZIP code1 and census tract2 to facilitate SEER-CMS analyses. The included area-level measures can be linked to the encrypted census tracts listed in the SEER-CMS Cancer File3 and encrypted ZIP codes listed in the Medicare administrative data4. The census tracts and ZIP codes across all SEER-CMS files are encrypted using the same process, which allows linkage across the files. To minimize small area reidentification and to protect provider and patient confidentiality, a random amount of error is added to the released area-level measures.

If a desired measure is not available in the below SEER-CMS area-level files, researchers can request unencrypted census tracts and/or ZIP codes to link with external datasets. Details on how to obtain unencrypted geographic identifiers can be found at Restricted or Special Permission Variables.

Historical Measures

Measures from the 1990 and 2000 Censuses at the census tract and ZIP code level are available, including information such as area-level population distribution, income, and education. For more information see:

More Recent Measures

NCI has compiled an expanded collection of area-level measures using more recent data sources. Briefly, the American Community Survey (ACS) 5-year rolling average data (e.g., 2008-2012: midpoint 2010 data) became the source for the previously released measures (e.g., population distribution, income, and education), given this information stopped being collected as part of the decennial census. Additional measures are now also available, including information on mortgage access (contemporary and historic), food access, environmental exposures, area walkability, general health status, and use of healthcare services. Measures were developed and downloaded from federal and non-federal websites, including the Centers for Disease Control and Prevention (CDC), the United States Department of Agriculture (USDA), and the Economic Research Service.

To minimize small area reidentification and to protect provider and patient confidentiality, researchers will not be granted access to all area-level files listed below. Researchers should examine the documentation below to identify which of the three area-level file types will best suit their needs: (1) Demographics & Employment; (2) Insurance & Health Status; (3) Housing & Mobility. Justification for the included measures must be provided in the application or update/change request form (for previously approved projects). Each of the three area-level file types include sub-files with measures from different data sources (e.g., if the Demographics & Employment Census Tract Files are requested, all related subfiles with be provided; subfiles are specific to data source, such as ACS, CDC, and USDA). Approval is granted at the area-level file type; when release of an area-level file type is approved, all sub-files and, thus, all sub-file variables, under the area-level file type will be provided to the requestor.

  • Demographics & Employment Census Tract Files Documentation (PDF (PDF, 693 KB) XLSX (XLSX, 30 KB))
  • Demographics & Employment ZIP Code Files Documentation (PDF (PDF, 764 KB) XLSX (XLSX, 26 KB))
  • Insurance & Health Status Census Tract Files Documentation (PDF (PDF, 266 KB) XLSX (XLSX, 23 KB))
  • Insurance & Health Status ZIP Code Files Documentation (PDF (PDF, 691 KB) XLSX (XLSX, 23 KB))
  • Housing & Mobility Census Tract Files Documentation (PDF (PDF, 867 KB) XLSX (XLSX, 39 KB))
  • Housing & Mobility ZIP Code Files Documentation (PDF (PDF, 360 KB) XLSX (XLSX, 21 KB))

Note: Users of 5-year American Community Survey estimates from the period 2018-2022 should be advised that the approach to adjusting for inflation for both median income and housing costs has varied over time. As a result, there may be a discontinuity in measurement between the 5-year estimates included for the 2013-2017 period and the 2018-2022 period. Please review the Census Bureau's data documentation for the 5-year ACS estimatesExternal Web Site Policy for additional information.

Dartmouth Atlas on Health Hospital Referral Regions (HRRs)

The Dartmouth Atlas on Health includes Hospital referral regionsExternal Web Site Policy (HRRs) that represent regional health care markets for tertiary medical care that generally requires the services of a major referral center. The regions were defined by determining where patients were referred for major cardiovascular surgical procedures and for neurosurgery. Each HRR has at least one city where both major cardiovascular surgical procedures and neurosurgery are performed. Upon request, a crosswalk between HRRs and encrypted zip codes can be provided so that HRR can be determined without receipt of unencrypted zip codes.

1 Most, but not all, area-level data sources rely on ZCTA codes. ZCTA codes, maintained by the Census Bureau, are geographic areas that are similar to, but not identical to, ZIP codes. ZIP codes may change annually, whereas ZCTA codes are updated based on the decennial census.

2 Census tracts are maintained by the Census Bureau and updated based on the decennial census.

3 Given census tracts change over time, the SEER-CMS Cancer File includes multiple census tract variables. Researchers are advised to use the census tract that most closely matches the year of cancer diagnosis (e.g., census tract 2010 for cancer diagnoses from 2006-2015).

4 The Medicare enrollment, claims, and encounter data include beneficiary and provider mailing ZIP codes, which may differ, respectively, from residential and place of service ZIP code.

Last Updated: 11 Dec, 2025