While co-design with users has evolved as a promising approach to service innovation, it remains unclear how it can be used in public service contexts. This article addresses this knowledge gap by applying a co-design framework during the ideation stage of six public service design projects. The findings provide insights into (a) recruiting and sensitizing suitable service users, (b) conditions enabling users to co-design ideas, and (c) requirements for implementation of user-driven ideas. The article contributes an approach that shifts public service design away from an expert-driven process towards enabling users as active and equal idea contributors.