For more than 30 years the collaboration between obstetrician–gynecologists and certified nurse–midwives at San Francisco General Hospital has led to the provision of high-quality care to women and families. This enduring partnership has been sustained by shared goals and values, most notably a commitment to excellence in both providing care to the underserved and training the next generation of physicians and nurse–midwives. Success has also depended on a mutual respect for differences that has enabled the collaborative to capitalize on the distinct expertise of each partner. The balance struck between independence and interdependence of the practice groups has led to innovation and successes that might otherwise not have come to being, while also enabling the collaborative to overcome the inevitable conflicts and challenges that arise within this type of long-standing partnership. This model holds promise for replication in other settings and informs broader considerations of health policy and regulation.