SEER-Medicaid: SEER Program & Data

Overview of SEER

The SEER Program is an epidemiologic surveillance system consisting of population-based tumor registries designed to track cancer incidence and survival in the United States. Collection of the SEER data began on January 1, 1973. The registries routinely collect information on newly diagnosed cancer patients residing in geographically defined areas.

SEER Data

The SEER data released as part of SEER-Medicaid contain information about each incident cancer diagnosis (e.g., cancer site, histology, and stage) and cancer-directed surgery provided as first course of treatment. The registries collect information about all primary cancer diagnoses. The SEER data do not capture information about recurrence or metastasis that is detected subsequent to the initial diagnosis. For more information about the SEER program and data, please see the SEER Home Page.

Individuals were included in the SEER-Medicaid linkage if they had an index cancer diagnosis reported to a SEER registry between 1999-2021; however, information on all cancer diagnoses reported to SEER for the included individuals are available in the SEER-Medicaid Cancer File (PDF, 1.4 MB).

• The SEER-Medicaid Cancer File includes persons who were found in both SEER and Medicaid data (i.e., persons with cancer who had Medicaid coverage at some point during the included data years).
• The SEER Cases-Unlinked (Controls) File includes persons who were in the SEER data but not in the Medicaid data (i.e., persons with cancer who never had Medicaid coverage during the included data years). These persons can serve as a non-Medicaid cancer control population.

NOTE: The same SEER data are available for both sets of persons with cancer.