Purpose: The added value of measuring patient-reported outcomes (PROs) for delivering patient-centered care and assessment of healthcare quality is increasingly evident. However, healthcare system wide data collection initiatives are hampered by the proliferation of patient-reported outcome measures (PROMs) and conflicting data collection standards. As part of a national initiative of the Dutch Ministry of Health, Welfare and Sport we developed a consensus-based standard set of generic PROs and PROMs to be implemented across Dutch medical specialist care. Methods: A working group of mandated representatives of umbrella organizations involved in Dutch medical specialist care, together with PROM experts and patient organizations worked through a structured, consensus-driven co-creation process. This included literature reviews, online expert and working group meetings, and feedback from national patient- and umbrella organizations. The ‘PROM-cycle’ methodology was used to select feasible, valid, and reliable PROMs to obtain domain scores for each of the PROs included in the set. Results: Eight PROs across different domains of health were ultimately endorsed: symptoms (pain & fatigue), functioning (physical, social/participation, mental [anxiety & depression]), and overarching (quality of life & perceived overall health). A limited number of generic PROMs was endorsed. PROMIS short forms were selected as the preferred instruments for all PROs. Several recommendations were formulated to facilitate healthcare system level adoption and implementation of the standard set. Conclusions: We developed a consensus-based standard set of Generic PROMs and a set of recommendations to facilitate healthcare system wide implementation across Dutch medical specialist care.