The process of innovation implementation within organizations is fraught with challenges in contextual factors such as organizational climate and employee attitudes and behaviors. An approach to limit these issues and gain greater overall implementation effectiveness is to build upon and utilize knowledge of contextual factors within workgroups that might affect individual implementation outcomes such as attitudes toward an innovation and intentions to implement said innovation. A cross-level moderated-mediation model of implementation within workgroups and individuals was explored; whereas, workgroup implementation climate strength and psychological safety climate were expected to moderate workgroup implementation climate level’s direct and indirect effects with individual member attitudes toward an innovation and their implementation intentions. An archival sample of 37 Substance Use Disorder Treatment (SUDT) workgroups comprised of 169 individual SUDT providers from the Leadership and Organizational Change for Implementation (LOCI) study (NIH Grant: R01DA038466) were used. Data were from Cohort 1 and Cohort 2 baseline surveys, collected in 2016 and 2017 at five SUDT agencies preparing to implement Motivational Interviewing (MI) ® into daily use. Workgroup implementation climate level was found to be significantly related to individual implementation intentions (B = .597; p < .05). Statistical support was also found for a positive relationship between individual providers’ attitudes toward MI and their intentions to implement MI (B = .768; p < .001). The relationship between workgroup implementation climate level and individual providers’ attitudes toward MI was trending toward statistical significance (B = .288; p = .088). As was the moderating effect of implementation climate strength on workgroup implementation climate level’s relationship with providers’ implementation intentions (B = -.827; p = .055). Lastly, there was no statistical support for the moderating effect of workgroup psychological safety climate on workgroup implementation climate level’s relationships with individual providers’ attitudes toward MI (B = -.102; p > .05) and implementation intentions (B = -.358; p > .05). The results of this thesis provide some evidence that workgroup implementation climate effects individual provider attitudes and implementation intentions. This thesis contributed to ongoing work concerned with increasing innovation implementation effectiveness within organizations.