In this paper we articulate and diagnose a previously unrecognized problem for theories of entitlement, what we call the Claims Conundrum. It applies to all entitlements that are originally generated by some claim-generating action, such as laboring, promising, or contract-signing. The Conundrum is spurred by the very plausible thought that a later claim to the object to which one is entitled is a function of whether that original claim-generating action is attributable to one. This is further assumed to depend on one’s being identical to the person who performed the claim-generating action. But the right theory of personal identity for grounding these later claims proves quite elusive. In demonstrating both the Claims Conundrum and diagnosing its source, we begin with its instantiation in John Locke’s theories of personal identity and initial acquisition, and then we gradually expand its net to include both Lockean and non-Lockean theories of both, moving ultimately to show that this is a problem for most entitlements generally. We then diagnose the source of the trouble, showing that a basic assumption about the link between attributability and identity that most people take to be obvious is in fact false, clearing a path for future investigation into this overlooked but serious problem’s resolution.