Designing an effective user interface to enter SNOMED CT® coded data is essential to achieving high quality data and implementation success. A variety of techniques can be adopted at the user interface, including the use of free text encoded via natural language processing (NLP) tools and structured data controls such as radio buttons, tick boxes, drop down lists and term searches. User interfaces should be designed to make it as efficient as possible for users to find the most relevant concept. This chapter explores different options, considerations, and principles for designing effective SNOMED CT® enabled user interfaces.