Project Summary The broad, long-term objective of this supplement is to Tackle Acquisition of Language In Kids (TALK), specifically, to better understand the developmental trajectory and needs of late-talkers. These are toddlers who are not using as many words as they should before the age of three. Late talking is associated with a host of later issues including poor academic outcomes. However, it is difficult to know which toddlers will grow to have persistent challenges, and whose challenges will resolve. This limits both our understanding of late talking and our ability to serve late talkers efficiently and effectively. Our first specific aim is to collect follow- up data from 50 of the late talkers formerly enrolled in our study to see how many are impaired or at-risk in terms of language, speech, reading, cognition, and educational outcomes months to years after our initial assessments. We will also use data from our original study to see if there are any early indicators that predict later outcomes, using CART analysis. We will use age-appropriate standardized measures that are either diagnostic or descriptive, as well as collecting educational records. This will be a more comprehensive examination of former late-talkers’ skills than is usually performed. Thus, we hope to have a more comprehensive picture of what development looks like for late talkers. For our second specific aim, we plan to collect qualitative data from family members of late talkers and the, now older, late-talkers to better understand the functional and social effects of having a Late Talker in the family and the lived experience of being a Late Talker. There is almost no work on the functional reality of parenting a late talker or being a late talker. We need to understand how this diagnosis impacts daily life. We will co-create interview questions with family members of late talkers in a focus group and use the questions to interview family members and late-talkers themselves. An evidence-based picture drawing protocol will be used as part of the interview process for the now-older late talkers. Data will be analyzed using thematic analysis. Finally, for our third specific aim, we plan to create a sharing protocol so that researchers studying late talkers can aggregate data to answer questions that require larger data sets than single labs can easily obtain. We will include input from other researchers studying late-talking to ensure the protocol will be useful and accessible.