GD&T: Application and Interpretation, based on the ASME Y14.5-2018 standard, is targeted to entry-level and advanced programs that require a study of geometric dimensioning and tolerancing as related to design, manufacturing, or inspection. The sequence of chapters is closely tied to the organization of topics in the ASME Y14.5 standard, with topics ranging from the fundamentals of dimensioning to the extended principles of tolerance application and interpretation. Illustrations are used extensively to clarify explanations in the text and show applications in three-dimensional (3D) models and orthographic views. The author is certified by ASME as a Senior Level Geometric Dimensioning and Tolerancing Professional and has participated in the development of national and international standards for more than 25 years.