TIMSS (Trends in International Mathematics and Science Study) is a long-standing international assessment of mathematics and science at the fourth and eighth grades, collecting trend data every four years since 1995. Over 70 countries rely on TIMSS to monitor their education systems in a global context, benchmarking national curricula and informing policy and practice. Building on the successful transition to digital assessment in 2023, TIMSS 2027 marks the second fully digital cycle, further harnessing technology to enhance data quality, improve operational efficiency, and strengthen the utility of results. The TIMSS mathematics and science frameworks are updated with each assessment cycle through a collaborative, expert-driven process to ensure alignment with current educational objectives, practices, and priorities across participating countries. At the same time, frameworks retain key elements to ensure valid measurement of achievement trends across cycles. Updates for TIMSS 2027 mathematics and science frameworks also include descriptions of the TIMSS problem-solving and inquiry tasks (PSIs) integrated within the broader discussion of the cognitive domains. The assessment also integrates more complex, interactive item types to capture problem-solving approaches and processes. These innovations leverage expanded capabilities in automated scoring, including machine learning for both graphical and written responses. The TIMSS 2027 Mathematics Framework presents the updated assessment frameworks for mathematics at the fourth and eighth grades. The TIMSS 2027 Science Framework, structured around the domains of biology, physical science, chemistry, and earth science, reflects current priorities in global science education. The TIMSS 2027 Contextual Framework outlines the comprehensive system for collecting background data on policies, classroom practices, and student learning environments that support and characterize students' mathematics and science achievement. The TIMSS 2027 Assessment Design features an innovative, digitally enabled approach, building on the group adaptive design introduced in TIMSS 2023. TIMSS 2027 builds on a strong tradition of providing assessments in mathematics and science at the fourth and eighth grades with updated content, an expanded use of digital tools, and an innovative test design. The frameworks reflect current educational priorities in mathematics while preserving the ability to report trends in student achievement. With enhanced item formats, adaptive testing, and enriched contextual questionnaires, TIMSS 2027 supports a comprehensive view of how educational systems prepare students to meet evolving curricular goals and instructional expectations around the world.