Each year, eligible individuals forgo billions of dollars in financial assistance in the form of government benefits. To address this participation gap, we identify psychological ownership of government benefits as a factor that significantly influences individuals’ interest in applying for government benefits. Psychological ownership refers to how much an individual feels that a target is their own. We propose that the more individuals feel that government benefits are their own, the less likely they are to perceive applying for them as an aversive ask for help, and thus, the more likely they are to pursue them. Three large-scale field experiments among low-income individuals demonstrate that higher psychological ownership framing of government benefits significantly increases participants’ pursuit of benefits and outperforms other common psychological interventions. An additional experiment shows that this effect occurs because greater psychological ownership reduces people’s general aversion to asking for assistance. Relative to control messages, these psychological ownership interventions increased interest in claiming government benefits by 20% to 128%. These results suggest that psychological ownership framing is an effective tool in the portfolio of potential behavioral science interventions and a simple way to stimulate interest in claiming benefits.