Disability assessment is a complex and multifaceted process of exploration and evaluation, which in terms of legal evidence can be of far-reaching consequence for the claimant, the statutory pension insurance and finally for society as well. In the article the specifics of the assignment, the assessment situation, and the process of evaluation are described. Based upon an analysis of the so far only little research activities, the future need for research is subdivided into 4 thematic groups: 1 Operationalization and validation of central dimensions of evaluation; 2 Investigation of the structure of the expert decision-making process and the factors influencing it; 3 Investigation of the influence of sociopolitical, labour market-related and economical aspects on the evaluation; 4 Quality assurance. On the other hand the article describes the special quality of disability assessment. In a unique way it offers an integrated reflection of the medical history, limitation in capacity and participation and options for treatment and rehabilitation. Beyond the assessment of functional capacity, it could be of use for the development of innovative forms of support for the rehabilitation of working capacity.