This session reflects R&D on User Centered Design and Development and User Participation (in short UCD in the following) for/with people with disabilities. Better guidelines, methods, techniques and tools are needed to improve the quality of R&D and practice both in the domain of Assistive Technology (AT), eAccessibility and eInclusion itself but also for improving the quality of mainstream R&D through UCD and participation of people with disabilities. We analyze the state of the art, identify gaps and problems as well as discuss examples and new approaches presented in 5 papers. The introduction integrates the topic into the broader context of UCD in Information and Communication Technology (ICT) and Human-Computer Interaction (HCI) playing a major role for AT, eAccessibility and digital inclusion. We underline the need for ongoing and more intense R&D on UCD to improve quality and usability. By promoting this session in the ICCHP conference series we aim at establishing a comprehensive point of access to scientific work in this domain.