REC - SUMMARY LHS training in primary care research and patient centered outcomes is urgently needed. Primary care is at the core of healthcare quality and is central to our ability to improve healthcare equity. Training in LHS research and PCOR methods is essential to addressing the needs of primary care teams and the patients, families and communities they serve. The Washington LHS E-STAR Center is uniquely poised to address these challenges through the synergy of training embedded scientists and building LHS capacity in primary care community health settings. E-STAR extends our successful K12 LHS training program (CATALyST), which mentored 8 scholars to be outstanding LHS researchers. We will recruit and retain a diverse set of 7 LHS scholars embedded in primary care settings serving AHRQ’s priority patient populations. These scholars will have multidisciplinary training for independent primary care research careers focused the quintuple aim of health equity, clinician well-being, better patient experience, improved population health, and lower costs. To focus on the primary care needs of underserved populations, we extend our current CATALyST research and mentoring partnerships with KPWA, the VA Puget Sound Health Care System, the University of Washington Schools of Public Health and Medicine to include the Schools of Nursing and Social Work and four Federally Qualified Health Centers. E-STAR will offer outstanding LHS training focused on equity and quality in primary care with an emphasis on recruiting and supporting scholars underrepresented in the scientific workforce. Scholars will master the eight LHS competencies with a focus on the newest competency of health and healthcare equity and justice. An outstanding set of mentors with expertise in LHS and primary care research will provide structured mentoring to scholars focused on their individual needs for LHS training. Experiential learning for scholars stresses a participatory approach, centering on primary care organizations' LHS needs and building strong partnerships. Our diverse and well-qualified candidate pool of scholars and strong history of collaboration across our partner organizations will provide a supportive learning environment for the next generation of LHS scientists.