A child’s diagnosis of autism spectrum disorder (ASD) often comes after months or years of worry and a long and painful search for answers. Receiving that final, official word can be very hard, even if parenta expected the diagnosis, or fought fiercely for the evaluation that led to it. As they begin to regroup, learning how to navigate education, medical, and insurance systems, they may also wonder: When will we tell our child about this diagnosis? When will we tell his brothers and sisters? How will we tell them?