The concept of the ‘million dollar block’ refers to the spatially concentrated urban origins of the US prison population, most of whom come from a handful of neighborhoods in the country’s biggest cities. Visualized through a series of maps charting home addresses alongside financial costs of imprisonment, the million dollar block has emerged as a powerful rhetorical umbrella for bipartisan collaboration on prison reform. This article critically tracks the way the million dollar block, as both a cartography and a discursive formation, has travelled politically over the past decade. Finding parallels with the ‘neighborhood effects’ discourse within urban studies, I suggest the million dollar block similarly functions to cast poor and racialized urban spaces primarily in terms of criminogenic risk. I describe how the discursive cartography of the million dollar block, despite its reformist intentions, serves a neoliberal model of prison reform, rationalizing increased carceral state intervention in urban space. [ABSTRACT FROM AUTHOR]