This chapter outlines a model regime of prior record enhancement (PRE), designed to promote more rational, parsimonious, and humane sentences. It provides general principles and specific rules reflecting what is known about PRE justifications, costs, benefits, and adverse consequences. The principles specify which punishment purposes justify PRE, while also recognizing the overarching importance of maintaining proportionality to conviction offense seriousness, ensuring that PREs are necessary and cost-effective, minimizing racial disparities and imprisonment of aging and nonviolent offenders, avoiding interference with offender efforts at desistance, and striking a reasonable balance between rule and discretion. The model’s PRE counting rules exclude juvenile and misdemeanor priors, convictions more than 10 years old, upweighting of felonies based on their severity or similarity, and custody status points. First offenders receive substantial sentence mitigation, after which PRE magnitude increases modestly and is capped. High-history offenders are punished no more than twice as severely as first offenders.