How important is self-interest in people’s opinions about public policy? If a policy proposal exempts a subset of the target group from costs that others will have to pay, or denies them benefits that others will enjoy, do they respond according to self-interest? This experimental study distinguishes between true self-interest and affinity for one’s in-group by exploiting a common feature of policy proposals: age-based “carve-outs” that prevent otherwise similar subgroups of a population from being affected by the benefits or burdens of a new policy (e.g., cuts to an old-age program that exempt people above a certain age). I find self-interest effects for older Americans exempt from cuts to Medicare and younger people too old to benefit from a hypothetical student debt relief program. These effects vary in ways that are consistent with extant theory.