In the final version of our article entitled, " Lessons from sexual and reproductive health voucher program design and function: a comprehensive review" the authors inadvertently failed to acknowledge the role of International Union of Scientific Study of Population (IUSSP). IUSSP colleagues kindly reviewed early drafts of the manuscript presented at an IUSSP workshop in Bangkok August 2012 and had specifically requested that we recognize their feedback. We therefore feel obliged to acknowledge IUSSP.