It is with great sadness that we announce that our esteemed colleague Dr. Michael Vlassoff, a Senior Research Scientist at the Guttmacher Institute, passed away suddenly over the 2016 Thanksgiving holiday. A demographer and health economist by training, Michael worked at UNFPA for many years, holding posts at the New York headquarters and at country offices, including India and Bhutan. During his 13 years with Guttmacher, Michael made important contributions to abortion incidence studies in Bangladesh and India and to the Institute’s flagship Adding It Up (AIU) reports. His AIU work included global research as well as country level-research on Ethiopia, Uganda, Malawi and Cameroon. He was also instrumental in work on the cost of postpartum hemorrhage treatment in Egypt and Senegal. In recent years his work also included estimating the cost of abortion-related morbidity, carrying out pioneering research on the costs of unsafe abortion both to health systems and to women and their households—research that has been cited extensively and been used to inform key program and policy discussions regionally and in a number of countries. You may learn more about Dr. Vlassoff’s work at the Guttmacher Institute through his biography page. We extend our deepest condolences to Michael’s family, his wife Carmen and his daughters Macarena, Nadya and Nicole. We shall miss him greatly.