In JAMA Network Open, Gold et al 1 share results from their cluster randomized clinical trial assessing the impact of CV Wizard, an electronic health record (EHR)-embedded clinical decision support system (CDSS), on cardiovascular risk reduction in patients served by community health centers (CHCs). By implementing a previously validated CDSS in underresourced health care facilities that predominantly serve socioeconomically vulnerable patients, the authors generated 2 particularly important findings. First, they found CV Wizard was used in only 19.8% of all eligible clinical encounters. Second, they found a modest (<1%) reduction in overall 10-year atherosclerotic cardiovascular disease (ASCVD) risk with CV Wizard use only among patients with baseline ASCVD risk of greater than 20%. In this commentary, we explain why both findings highlight the importance of using established implementation science conceptual frameworks when implementing CDSS in any health care setting, particularly in underresourced health care facilities such as CHCs. Gold et al 1 implemented CV Wizard in multiple CHC organizations as an intervention to change clinician and patient behavior important for reducing patients' ASCVD risk. In doing so, they had all the components of the practical, robust implementation and sustainability model (PRISM), a wellestablished implementation science framework, of Feldstein and Glasgow. 2 They had an intervention (CV Wizard), recipients (CHC clinicians and patients), an external environment (CHCs), an implementation infrastructure (EHR-embedded software), and concrete measures of reach and effectiveness (rates of use and reduction in patients' 10-year ASCVD risk). Under PRISM, successful adoption, implementation, and maintenance of any intervention depends on understanding and addressing contextual determinants (barriers and facilitators) to implementation: (1) patient and organization perspectives of the intervention, (2) relevant characteristics of the recipients (ie, CHC clinicians and patients), and (3) facilitating or barrier factors within the external environment. Before implementation of CV Wizard, Gold et al 1 met with CHC clinicians and EHR programmers every 2 weeks for a full year to identify and address a wide variety of legal, compliance, technical, and clinical implementation challenges. 3Despite their extensive preimplementation efforts, Gold et al 1 found that CV Wizard was used at only 19.8% of eligible clinical encounters within CHCs. Given that the intervention was an automated EHR alert containing the CV Wizard link provided to staff rooming eligible patients, and that simply viewing the information was counted as CDSS use, this means that 80% of alerts were left unheeded. Why this occurred in CHCs but not in other better-resourced health care facilities where CV Wizard rates of use have been closer to 70% to 80% 4 is unclear but critical to understand.The authors state that heterogeneity in rooming protocols between CHCs impeded efforts to train rooming staff and likely contributed to ...