How the SEER and Medicaid Data are Linked

The linkage of the SEER-Medicaid data is a collaborative effort of the NCI, the SEER registries, and the Centers for Medicare & Medicaid Services (CMS).

To link SEER with Medicaid data, the registries participating in the SEER program send individual identifiers for all persons included in their files (e.g., persons reported to have an incident cancer diagnosis). These identifiers are then matched with identifiers contained in CMS’s Medicaid master enrollment files. Enrollment information pertaining to overlapping individuals is then pulled together to create the SEER-Medicaid database. All personal identifiers are removed from the SEER-Medicaid database, prior to being released to requestors.