Abstract In response to PAR-20-080, NIMH Mentoring Networks for Mental Health Research Education, this application seeks five years of support to respond to training demand, continue scientific leadership to the field, and empower a new generation of leaders in implementation science for mental health services research. This network will extend in creative new ways the Implementation Research Institute (IRI, NIMH R25 funding 2009- 2015, 2016-2019), which has successfully trained 87 new mental health implementation researchers. Implementation science is critical for mental health where most Americans with mental disorder receive sub- optimal care due in large part to challenges in the implementation, sustainability, and scale-up of evidence- treatments. Training demand far outweighs supply but only a handful of programs train implementation researchers and only the IRI in mental health. Therefore we seek a five-year renewal of IRI to pursue three aims: (1) to continue a vibrant mentoring network of Faculty and Fellows who will advance the science and lead the workforce in mental health implementation research; (2) to accelerate training benefits and enhance IRI sustainment by elevating new mentoring leadership in implementation science, and (3) to evaluate training outcomes. We will achieve aim 1 by (a) conducting an innovative, continually renewed annual summer institute; (b) fostering networked collaboration and mentoring from faculty to fellow and peer to peer among IRI fellows; (c) supporting fellows’ travel to externally funded implementation research sites where they will learn from NIH Principal Investigators, thereby expanding their networks; and (d) equipping IRI fellows, via the Translational Science Benefit Model (TSBM), to map pathways for the public health impact of the MHSR implementation science in response to aim four of NIMH’s strategic plan. We will achieve aim 2 by using evidence-based mentoring and leadership development strategies to train an Associate Director designee and new core faculty designees, pairing them with seasoned core faculty and advancing them to mentoring leadership positions in implementation science. We will achieve aim 3 by using evaluation methods that include TSBM case studies, bibliometrics, social network analysis, and competency assessment to evaluate outcomes that include mentoring effectiveness, collaboration, translational benefits, and implementation science to scholarly products.