Analytic Strategy The present study utilized multilevel mediation models [ 33 ], which extend the classic mediation model to clustered data, in Mplus (version 8) via the type is two level specification. In this study, clustered data involved repeated measures collected from the same individuals over 14 days. We employed a two-level multilevel model to address the study’s central questions. Level 1 represented variability due to within-person repeated measures for persons with TD, and Level 2 represented between-person variability across persons with TD [ 28 ]. At each level, we specify a mediation model allowing for distinct mediation at Level 1 and Level 2, a mediation model of within person variation and a mediation model of between people variation. This is equivalent to a mediation model where sleep quality, self-regulation failures, and self-care behaviors were person centered and the between person means (removed due to centering) are also included as a mediation channel. First, we used single mediator multilevel mediation models to examine whether the daily associations between sleep quality was associated with self-care behaviors and whether this association was mediated through self-regulation failures at both within-person and between-person levels. Second, we used sequential multiple mediator multilevel mediation models to examine whether self-regulation failures and self-care behaviors mediated daily relationships between sleep quality and BG levels sequentially at both within-person and between-person levels. Results First, we ran unconditional models to calculate intraclass correlation coefficients (ICCs) and examined within- and between-person variability in daily sleep quality, self-regulation failures, self-care behaviors, BG mean, and ADDR across the 14 diary days. There was both within- person (67.57%) and between-person variability (32.43%) in daily sleep quality. There was also both within- and between-person variability in measures of daily self-regula- tion failures (37.61% within 62.39% between, daily self- care behaviors (31.87% within 68.13% between, daily BG mean (69.39% within 30.61% between, and daily ADRR (69.22% within 30.78% between).