Mosaic™ by ACT® Social Emotional Skills Assessment (hereafter called Mosaic) measures five key social and emotional (SE) skills: Sustaining Effort, Getting Along with Others, Maintaining Composure, Keeping an Open Mind, and Social Connection. This assessment includes three distinct item types--Likert, situational judgment test, and forced choice--to derive an aggregate score for each SE skill. Some validity evidence for these aggregate scores was previously reported in the Mosaic technical manual (ACT, 2021), but now new data are available to further evaluate the scores' convergent, discriminant, and test-criterion validity and to highlight the importance of SE skills for predicting important outcomes.