Large-scale assessment programs, such as the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS), employ item response theory (IRT) and marginal estimation methods to estimate student proficiency in specific subjects such as mathematics, science, or reading. Each of these subjects is defined by a framework that specifies the subject's content areas and, within each content area, the topics that are covered. The purpose of this report is to introduce a method for analyzing student achievement at the topic level using data from TIMSS assessments. Reporting topic-level scores in large-scale assessments, such as TIMSS, would be tremendously valuable from both a policy and pedagogical perspective. Topic-level scores could allow one to pinpoint areas in which students are excelling or struggling more specifically than is possible when one looks at just content area scores. Analysis of topic-level scores could reveal the strengths and weaknesses of students in relation to the intended and actualized curricula. TIMSS collects and reports contextual information about both the intended curriculum at the topic level and which topics teachers report that students have been taught. Trends in topic-level scores across years and between countries could also help more fully realize the promise of monitoring system-level performance in an "actionable" way.