BACKGROUND:Since 1990, the National Cancer Institute (NCI) and Centers for Medicare and Medicaid Services (CMS) have collaborated to create linked data resources to improve our understanding of patterns of care, health care costs, and trends in utilization. However, existing data linkages have not included measures of patient experiences with care. OBJECTIVE:To describe a new resource for quality of care research based on a linkage between the Medicare Consumer Assessment of Healthcare Providers and Systems (CAHPS®) patient surveys and the NCI's Surveillance, Epidemiology and End Results (SEER) data. DESIGN:This is an observational study of CAHPS respondents and includes both fee-for-service and Medicare Advantage beneficiaries with and without cancer. The data linkage includes: CAHPS survey data collected between 1998 and 2010 to assess patient reports on multiple aspects of their care, such as access to needed and timely care, doctor communication, as well as patients' global ratings of their personal doctor, specialists, overall health care, and their health plan; SEER registry data (1973-2007) on cancer site, stage, treatment, death information, and patient demographics; and longitudinal Medicare claims data (2002-2011) for fee-for-service beneficiaries on utilization and costs of care. PARTICIPANTS:In total, 150,750 respondents were in the cancer cohort and 571,318 were in the non-cancer cohort. MAIN MEASURES:The data linkage includes SEER data on cancer site, stage, treatment, death information, and patient demographics, in addition to longitudinal data from Medicare claims and information on patient experiences from CAHPS surveys. KEY RESULTS:Sizable proportions of cases from common cancers (e.g., breast, colorectal, prostate) and short-term survival cancers (e.g., pancreas) by time since diagnosis enable comparisons across the cancer care trajectory by MA vs. FFS coverage. CONCLUSIONS:SEER-CAHPS is a valuable resource for information about Medicare beneficiaries' experiences of care across different diagnoses and treatment modalities, and enables comparisons by type of insurance.