In this chapter, we show how this relatively recent, national intervention has strived to alter the developmental trajectories of thousands of infants and toddlers in low-income families. We show how EHS has the potential for altering the life course of infants and toddlers in poverty in all the areas of development commonly associated with kindergarten readiness. We show how evidence from the EHS national evaluation demonstrates not only significant gains by age 3 when families complete their enrollment in EHS programs but also gains that are maintained 2 years later. We show that, indeed, preparations for school readiness begin during the infant-toddler years, but caution that the continuation of these gains into the school years does not happen automatically. Finally, in summarizing the implications of these findings for delivering effective infant-toddler programs, we show areas in which EHS programs need to be strengthened if they are to have stronger and broader benefits for the children and families they serve. (author abstract)