How does a joint sponsor fill out an I-864 Affidavit of Support for a step grandchild? My son petitioned for his wife and her child for Adjustment of Status. They had their interview last week and the officer told them that I need to submit another I-864 for my step grandchild, but I'm confused about several things. First, who am I supposed to put as the "principal immigrant" in part 2? I assume the child? Next, in part 3 it says "I am sponsoring the following family members immigrating at the same time or within 6 months of the principal immigrant named in part 2. Do not include any relative listed on a separate visa petition." That seems to say NOT to list the principal immigrant again but if I don't, then it would conflict with part 5 where it asks for "Persons you are sponsoring in this affidavit" which should be 1 but by obeying the form seems to be 0, and that also messes up the household size in number 8 of part 5. Please shed some light on this matter for me. The officer needs this back this week and I have to mail it from out of state.

If there are separate petitions for his spouse and his child, then you would submit two I-864s, one for each petition. If he is a U.S. citizen, then he must have filed separate petitions. If you file two I-864s, one for each petition, then on each I-864, you would only count the immigrant (there is only 1 immigrant on each petition in this case) for that petition, and not count the immigrant from the other petition in your household size.