PROJECT SUMMARY/ABSTRACT This NIMHD Mentored Research Scientist Career Development Award (K23) for Dr. Allyn Bove, an Assistant Professor of Physical Therapy at the University of Pittsburgh School of Health and Rehabilitation Sciences, will establish Dr. Bove as an independent health equity investigator with expertise in health disparities in musculoskeletal rehabilitation and use of implementation science methods to trial strategies to mitigate disparities. The proposed research aligns with several of NIMHD’s research interests related to clinical and health services research. This multi-level health services research project aligns with NIMHD’s goals to pursue “multilevel interventions” that seek to “increase health equity” and “improve access to or quality of care for populations affected by health disparities”. It also aligns with NIMHD’s pursuit of “research to understand barriers and facilitators to the adoption of and adherence to evidence-based practices and interventions in healthcare settings”. The research proposed in this four-year K23 award will occur in three phases. In the first aim, we will engage with provider and patient partners to identify barriers and facilitators to implementing optimal post-arthroplasty rehabilitation care pathways designed to improve outcomes and mitigate outcomes disparities based on patient race and income/insurance status. In the second stage, we will combine our preliminary data with information from Aim 1 to develop an evidence-based approach for equitable implementation of optimal rehabilitation care pathways to reduce disparities in community-based rehabilitation and physical function after arthroplasty. In the final step, we will pilot test implementation of these evidence-based novel rehabilitation care pathways. This work is important because it will progress rehabilitation disparities research beyond simply identifying differences toward designing and implementing novel interventions to reduce disparities and improve patient outcomes. The proposed work draws on Dr. Bove’s prior research on health disparities, qualitative research methodology, and rehabilitation for individuals with osteoarthritis and joint arthroplasty. This work will extend Dr. Bove’s work into the development and implementation of multi-level interventions to address health disparities in this population. Upon conclusion of the proposed research, formal training and mentorship outlined in this K23 application, Dr. Bove will be well- positioned to seek R01 funding for a large hybrid effectiveness/implementation trial of these care pathways that are designed to maximize function and promote equity in outcomes after hip and knee arthroplasty surgery.