The research-ready T-MSIS Analytic Files (TAFs) contain data on Medicaid and Children's Health Insurance Program (CHIP) beneficiary demographics, program enrollment, service use, and payments. In consultation with Medicaid policy and data subject matter experts, they were designed to meet the diverse research needs of the Medicaid and CHIP data user community. As the next generation of research-ready national data on these critical programs, they replace the Medicaid Analytic eXtract (MAX) files. The TAFs currently include 5 files, an enrollment file and four claims files. The annual Demographic and Eligibility (DE) file contains demographic, eligibility and enrollment information for all Medicaid and CHIP beneficiaries enrolled for at least one day during each calendar year. The Inpatient (IP) file, Long-Term Care (LT) file, Pharmacy (RX) file, and the Other Services (OT) file contain fee-for-service claims, managed care encounter claims, and per-person-per-month capitated payments for Medicaid and CHIP services, organized by service month.