Some data files are available as far back as 1987, but the Centers for Medicare and Medicaid Services (CMS) no longer provides technical support for files with data prior to 1991.
Mode of Collection
Abstraction of administrative/claims data.
Medicare administrative data or Medicare Fee-for-Service claims (administrative) data, also known as health services utilization data, are collected by the Centers for Medicare and Medicaid Services (CMS) and derived from reimbursement information or the payment of bills. Claims data are clinically valid and include various key attributes related to care such as admission and discharge dates, diagnoses and procedure codes, source of care, date of death, and demographic data (e.g., age, race and ethnicity, place of residence). Medicare claims data can be linked to various other data sources from the U.S. Census Bureau, the Veteran's Administration (VA), the National Death Index (NDI), and the Surveillance, Epidemiology, and End Results Program (SEER).
Enrollment data are for all persons enrolled in the Medicare program. Claims data include data for Medicare fee-for-service beneficiaries who filed claims. Claims data are not included for beneficiaries enrolled in managed care plans.