Background: In 2006 a major healthcare reform was introduced in the Netherlands, implying managed competition. This study explored the level of consensus on the outcomes and desired changes of this new system, and differences between stakeholder groups. Methods: A three-round Delphi-study was conducted among Dutch healthcare insurers, health economists, and professionals in general practice (GP) care and mental health (MH) care. In the first round, 20 experts indicated the most important advantages and disadvantages of the Dutch managed competition, and desired changes. Experts in the second (n = 106) and third round (N = 88) rated the importance of the 88 factors identified in the first round. Results: Only healthcare insurers reached consensus on important advantages (i.e. improved efficiency; room for choice). Health economists reached almost no consensus on any factors. GP and MH-care professionals reached most consensus on disadvantages (i.e. focus on price over quality, increased bureaucracy) and desired changes (i.e. reduce bargaining power of healthcare insurers; increase attention for care of complex patients); half of them suggested abolishment of managed competition. Conclusion: GP and MH-care professionals were most dissatisfied and suggested several changes or even abolishment of the 2006 reform; healthcare insurers mentioned some benefits. This level of dissatisfaction among health care professionals indicates that there is room for improvement, preferably developed in conjunction with stakeholders.