The Robert Wood Johnson Foundation (RWJF) is an American philanthropic organization. It is the largest one focused solely on health. Based in Princeton, New Jersey, the foundation focuses on access to health care, public health, health equity, leadership and training, and changing systems to address barriers to health. RWJF has been credited with helping to develop the 911 emergency system, reducing tobacco use among Americans, lowering rates of unwanted teenage pregnancies, and improving perceptions of hospice care.