This study investigates post-earthquake damage and the probability distribution of categorical damage states. Specifically, it demonstrates that the beta distribution is a good model for characterizing the complete range and probability distribution of damage states conditioned on ground-motion intensity. Based on extensive post-earthquake damage surveys following the 2010 earthquake in Haiti, the paper proposes a Method-of-Moments and a Maximum Likelihood Estimate-based formulation to fit a beta distribution model to grouped categorical damage data. The study further investigates goodness of fit for the beta distribution model compared to the binomial distribution model, often used to characterize the distribution of damage states in earthquake loss or risk analysis.