What population is included in CMS Medicaid data files?
The CMS Medicaid enrollment and claim files, State Medicaid Research Files (SMRFs), contain data for Medicaid eligibles who actually enroll. SMRF or MAX cannot, therefore, be used to study individuals who are eligible but not enrolled. The National Health Interview Study or the National Medical Expenditure Survey both collect data that may enable study of persons eligible for Medicaid. Since the CMS SMRFs document enrollment and utilization of Medicaid-paid services, it is not possible to study the health care utilization of Medicaid enrollees prior to enrollment or during periods when enrollment or eligibility lapses.
