Implementing new occupations in social care services as a solution to social problems challenges the knowledge base for social care. This has been particularly evident in services for persons with disabilities. Social policy has emphasized influence over services for persons with disabilities and hence has implemented personal assistance and case management services. Using these as examples, this article explores the professional logic developed, and the ways it relate to existing social professions. The results are presented in a typology defining two occupations as examples of a professional logic based on users’ knowledge. This logic, here called ‘user-mandated professionalism’, is denoted by wide discretion, relationships with users built on trust, and legitimacy mainly stemming from user organizations. The analysis then raises the challenge for social professionals in social care occupations based on users’ knowledge to be explicit about the knowledge base they build on in their arguments and in decision-making.