“A qualifying relative can be:a) a child [including stepchild and certain foster children] or a descendant of a child of the taxpayer;b) a brother, sister, stepbrother, or stepsister of the taxpayer;c) the father or mother of the taxpayer, or an ancestor of either;d) a stepfather or stepmother of the taxpayer;e) a son or daughter of a brother or sister of the taxpayer;f) a brother or sister of the father or mother of the taxpayer;g) a son-in-law, daughter-in-law, father-in-law, mother-in-law, brother-in-law, or sister-in-law of the taxpayer; orh) another individual with the same principal residence as the taxpayer who is a member of the taxpayer’s household [so long as the relationship between such individual and the taxpayer is not a violation of local law.”

Glaser, D.M. (2004). Re-defining “dependent”: Unexpected impact on benefit plans. New York Law Journal, December.