Eligibility criteria determine a crucial question for all voluntary assisted dying frameworks: who can access assistance to die? This article undertakes a critical and comparative analysis of these criteria across five legal frameworks: existing laws in Victoria, Western Australia, Oregon and Canada, along with a model Bill for reform. Key aspects of these criteria analysed are capacity requirements; the nature of the medical condition that will qualify; and any required suffering. There are many similarities between the five models but there are also important differences which can have a significant impact on who can access voluntary assisted dying and when. Further, seemingly straightforward criteria can become complex in practice. The article concludes with the implications of this analysis for designing voluntary assisted dying regulation. Those implications include challenges of designing certain yet fair legislation and the need to evaluate voluntary assisted dying frameworks holistically to properly understand their operation.