Owing to the recent development of artificial intelligence (AI), especially deep learning technology, multimodal user interfaces (UIs) are increasingly used as intelligent tools for systems requiring improved usability. Human-machine interaction is also critical in the domains of services for persons with age-related disabilities, including various devices. Therefore, UIs should be designed for various users and their tasks, based on the characteristics of users, tasks and devices. The AI technologies will help to devise trustworthy and convenient UIs in the corresponding care services for persons with age-related disabilities. This Recommendation introduces intelligent user interface (IUI) services for persons with age-related disabilities. In order to support such various IUI services, it reviews use cases and proposes requirements, and then defines common components and characteristics of IUI services.