People with significant cognitive disabilities and others who advocate on their behalf routinely state their claims in terms of enabling people to claim their full citizenship. Informed by the results of a study by one of the authors, we draw attention to some of these claims, and discuss what a just society ought to do so that members with significant cognitive disabilities see themselves – and are seen by others – as full, and therefore equal, citizens. Several political philosophers have sought to develop disability-inclusive accounts of justice, using three strategies: (1) defend a permissive understanding of who is owed justice by rejecting contribution to social cooperation as a necessary condition; (2) defend a permissive understanding of what counts as contribution; and (3) argue that some demands of justice are owed to all, while others are owed only to cooperators. We defend a version of the second strategy, arguing that the relevant notion of contribution requires that it be something the agent chooses to do because they know it to be valued by someone else, and we argue that the third strategy also has a role to play.