Vulnerable consumers may face barriers to using electronic payments, especially consumers in “unbanked” households where no member has an account to receive payments. In March 2013, the US Social Security Administration transitioned exclusively to electronic payments, representing a large shift in payment mode mandated at the federal level. This study identifies the size and characteristics of the population impacted by this shift, by linking administrative data on Social Security payments to a nationally representative survey on the use of bank accounts and financial services. We find that the majority of unbanked Social Security recipients took up electronic payments well before the March 2013 deadline. The mandate does not appear to have increased the use of bank accounts. Instead, recipients used electronic payment cards. However, the transition to electronic payments was slowest among the most financially vulnerable households, suggesting a focus on these households as payment methods continue to develop.