Despite efforts to ensure health workers have the skills needed to provide proper breastfeeding counseling and support to mothers, health workers may struggle to maintain and apply these skills in daily practice without continual support. The Kenya Ministry of Health Division of Family Health, Wellness, and Nutrition; implementing partners; and USAID Advancing Nutrition co-created a breastfeeding counseling mentorship program to reinforce and build the competencies required by health workers to implement the Ten Steps at health facilities offering maternal and newborn services. Together with these stakeholders, we are testing the feasibility of the mentorship program through implementation research as a potential approach to sustainably strengthen health worker breastfeeding counseling competencies in Kenya.