Reflecting disparities across the US, in 2015 publicly insured patients of the NorthShore Community Health Center (NSCHC) in Evanston, Illinois had lower breastfeeding rates than commercially insured patients. We used the Replicating Effective Programs framework to describe the design and implementation of a clinically-integrated breastfeeding peer counseling (ci-BPC) program to address these disparities. Patient focus groups and surveys informed program design, and a multidisciplinary clinical support team developed workflows that integrated the breastfeeding peer counselor (BPC) into the clinic and the postpartum unit. ci-BPC improved breastfeeding intensity and duration by providing every NSCHC patient with (1) prenatal lactation education; (2) hands on lactation care in the hospital; and (3) on-demand postpartum support. Total cost per patient was $297-386. The program was sustained after demonstrating potential cost-savings. An evidence-based, multidisciplinary collaboration resulted in a sustainable clinically integrated breastfeeding peer counseling program that improved breastfeeding outcomes.