My dependent is 21, disabled, and receives a child benefit from his fathers SSDI claim. He received $5,484.00 in 2016. Where do I enter my sons SSA-1099? in child depend

My son is Autistic and does not work. I am not married to his father. His father receives disability income and because my son is disabled, he receives a child/dependent payment from SSA. In 2016 my son received a total of $5,484.00. Where do I enter this information from a FORM SSA-1099 ?