This chapter presents and discusses important challenges to sufficientarianism as a theory of distributive justice. First, the groundlessness objection claims that sufficientarianism cannot reasonably be grounding on any relevant value. Second, the outweighing priority objection says that sufficientarianism implausibly allows small benefits to people below the threshold to outweigh large benefits to people above it. Third, the indifference objection observes that sufficientarianism is counterintuitively indifferent to even significant inequalities above the threshold. Finally, the threshold problem refers to the difficulty in identifying and justifying the threshold. The chapter responds to all these objections and concludes that sufficientarianism is largely unmoved by them. The chapter argues that the response to the indifference objection uncovers a minor intuitive problem in relation to sufficientarianism’s ability to explain the asymmetry between benefit-driven and burden-driven inequalities at high levels. And, that the threshold problem is not in and of itself an objection to sufficientarianism but rather an essential part of the development of sufficientarian theory.