This book explores the concept of financial capability as it applies to the well-being of low-income and financially vulnerable households in the United States. Social workers have only recently begun to apply the concept of financial capability to low-income households in the United States, and are beginning to understand how to build the financial capability of low-income households. One question that has already emerged from discussions within social work on financial capability is "What are the discrete and summative contributions of individual ability and financial inclusion to the well-being of low-income households?" This book explores the concept of financial capability, describes its theoretical foundations, and reviews the empirical literature on summative and discrete contributions of financial knowledge and financial inclusion to the well-being of low-income households.