Thinking about the rich social dimensions of ordinary, everyday cash use at the micro level suggests that fungibility is not an automatic function of money, but money’s goal. Fungibility is something that must be achieved. Cash denominations can perhaps be imagined as falling on a fungibility spectrum, ranging from “immediately fungible” on one end, to “fungible through extensive intersubjective mediation” on the other. The many intermediate steps one often needs to take to achieve money’s fungibility in Colca are socially significant, culturally generative, and ethnographically revealing.