This chapter documents changes in school readiness among entering kindergarteners across the years 1998-2010, a period characterized by dramatic changes to the early childhood landscape. I use a broad definition of school readiness that includes not only academic skills such as reading and math knowledge but also social and emotional skills and physical health. The most striking changes over time are large increases in children's math and literacy proficiency. These gains were even larger among low-income and black children, suggesting that early income and race-based achievement gaps have narrowed over time. However, this chapter also documents some concerning trends over time. Children's self-control and their approaches toward learning got worse across this period. Children were also more likely to be obese or overweight in 2010 than in 1998. These increases were largest among low-income and minority children, so racial/ethnic and income-based gaps in obesity have gotten larger. Taken together, the evidence suggests that children's school readiness has improved in some ways and declined in others across the years considered. Implications for policy and practice are discussed. [This paper was published in: A. J. Mashburn, J. LoCasale-Crouch, and K. C. Pears (Eds.). "Kindergarten Transition and Readiness: Promoting Cognitive, Social-Emotional, and Self-Regulatory Development." Cham, Switzerland: Springer International.]