Abstract: Most prenatal preventive interventions for unmarried mothers do not integrate fathers or help the parents plan for the development of a functional coparenting alliance after the baby’s arrival. Furthermore, properly trained professionals have only rarely examined the fidelity of these interventions. This report examines whether experienced community interventionists (home visitors, health educators, fatherhood service personnel) with no formal couples’ therapy training are capable of pairing together to deliver with adequate fidelity a manualized dyadic intervention designed for expectant unmarried mothers and fathers. Three male and four female mentors (home visitors, health educators, fatherhood personnel) working in paired male–female co-mentor teams delivered a seven-session “Figuring It Out for the Child” curriculum (six prenatal sessions, one booster) to 14 multirisk, unmarried African American families (parent age ranging from 14 to 40). Parental well-being and views of fatherhood were assessed before the intervention and again 3 months after the baby’s birth. Quality assurance analysts evaluated mentor fidelity (adherence to the curriculum, competence in engaging couples with specified curricular content) through a review of the transcripts and audiotapes from the sessions. Mentors also rated their own adherence. Although the mentors overestimated adherence, quality assurance analyst ratings found acceptable levels of adherence and competence, with no significant male–female differences in fidelity. Adherence and competence were marginally higher in sessions that required fewer direct couples’ interventions. Parents reported satisfaction with the interventions and showed statistically significant improvement in the family dimensions of interest at 3–4 months posttreatment. Findings support the wisdom of engaging men both as interventionists and as recipients of prenatal coparenting interventions—even in families where the parents are uncoupled and non-co-residential.