Background: Early care and education (ECE) quality has been a topic of discussion for several decades (Burchinal, 2018; Mashburn et al., 2008; NICHD ECCRN, 2002). The structure-process-child outcomes theory proposes that structural features (e.g., teacher education, class size) of quality predict process quality (e.g., teacher-child interactions), which in turn, predicts children's academic and behavioral outcomes. Policy has been responsive to research focused on quality in ECE, which has led to the development of ECE policies regulating both structural and process quality. In particular, Quality Rating and Improvement Systems (QRISs) and Head Start's Program Performance Standards incorporate both aspects of quality in their guidelines for ECE programs (Build Initiative, n.d.; OHS, 2016). Many of the previous studies that examined the link between ECE quality and children's outcomes were published prior to extensive policy changes (LoCasale-Crouch et al., 2007; NICHD ECCRN, 2002). Thus, updated research is needed to understand whether the structure-process-child outcomes theory translates into outcomes in the current ECE landscape. For example, Head Start adopted the CLASS (Pianta et al., 2008) as an accountability tool in 2013, which required programs to score above certain thresholds on each of the three CLASS domains to receive and maintain federal funding (OHS, 2010). Research Questions: We aimed to empirically test the structure-process-child outcomes theory. In addition, we examine these models within a Head Start policy context. Our research questions are: (1) To what extent do structural features of quality predict process quality in a Head Start context?; (2) Do process features of quality in Head Start lead to changes in children's school readiness?; (3) Within a Head Start policy context, do structural features of quality predict CLASS thresholds?; and (4) To what extent do CLASS thresholds predict children's academic and behavioral outcomes? We hypothesize that structural features of quality will predict higher levels of process quality, and there will be positive associations between indicators of process quality and children's outcomes in general and within the Head Start quality thresholds context. Data: Our study relied on data from the Head Start Family and Child Experiences Survey (FACES) 2014 study. The FACES study collected nationally representative data on a sample of Head Start programs, centers, classrooms, and 3- and 4-year old children. A total of 176 programs, 667 classrooms, and 2,462 children were sampled in the FACES 2014 study. Descriptive statistics are presented in Table 1. Research Design and Analysis: We conducted ordinary least squares regression analyses to examine the association between structural quality, process quality, and child outcomes. The structural quality variables included class size, child-teacher ratio, days per week class meets, teacher education level, teacher field of highest degree, teacher has child development associate credential, and total professional development (PD) supports offered; these variables were teacher-reported in the Spring of 2015. Process quality was measured using the ECERS-R (Harms et al., 2005) and the Pre-K CLASS (Pianta et al., 2008). Classroom quality was assessed by trained observers during the Spring of 2015. Child outcomes were assessed during the Fall of 2014 and Spring of 2015. We included numerous classroom-, teacher-, and child-level covariates in our analyses. For our study, we included the following measures of children's academic and behavioral development: Peabody Picture Vocabulary Test-Fourth Edition (PPVT-4; Dunn et al., 2006), Expressive One-Word Picture Vocabulary Test-4 (EOWPVT-4; Martin & Brownell, 2010), Woodcock Johnson III Tests of Achievement (WJ-III; Woodcock et al., 2001) Letter-Word ID, Applied Problems, and Spelling subtests, teacher-reported Social Skills Rating System (SSRS; Gresham & Elliott, 1990), and teacher-reported behavior problems. To examine the competitive CLASS thresholds identified by Head Start program guidelines, we transformed the CLASS variables to become dichotomous, where 1 = above the competitive threshold and 0 = below the competitive threshold. The competitive threshold for the Emotional Support and Organization Score domains is 5, and the competitive threshold for the Instructional Support domain is 2.3. Findings: Overall, we find little evidence to support the structure-process-child outcomes model as defined by the current ECE policy landscape. One structural indicator of quality, days per week class meets, was significantly, positively associated (p < 0.05) with the ECERS-R. To answer our second research question, we find that process quality did not lead to changes in the majority of children's academic and behavioral outcomes. Results are presented in Table 2. We did find one significant result for the WJ Applied Problems score where CLASS Instructional Support was significantly, positively associated (p < 0.05) with children's Applied Problems score. Finally, we find little support that CLASS thresholds are associated with either structural features of quality or child outcomes. We find largely null results for structural features of quality predicting CLASS thresholds. We had one significant finding for the competitive CLASS Emotional Support Threshold where days per week class meets was significantly, positively associated (p < 0.01) with CLASS Emotional Support Threshold scores. We did not find any evidence that CLASS thresholds predicted children's academic or behavioral outcomes. Conclusions: Our largely null results suggest a lack of relationship between structural and process quality. Additionally, neither continuous process quality measures nor CLASS thresholds were consistently predictive of children's school readiness. Our results hold important implications for ECE policy, since a significant amount of resources have been allocated to developing standards related to structural and process features of quality in ECE programs. Specifically, our findings add to a growing body of research which presents null or mixed results when examining the association between indicators of structural or process quality and children's outcomes (McDoniel et al., 2022). Continuous null or mixed findings suggest ECE policies should be reviewed and revised to reflect the updated research related to quality in ECE programs. Further, our study utilizes the most recent data available to understand to what extent competitive CLASS thresholds in Head Start are associated with structural features of quality and children's outcomes. Our overall null results align with prior research suggesting scoring above competitive thresholds may not consistently lead to changes in children's outcomes (Burchinal et al., 2016; Hatfield et al., 2016).