Adopted Children

Foreign children adopted by American families (residing in the US or abroad) never became US citizens "automatically." They have to be naturalized using one or other of two possible procedures (as explained here). For families residing in the USA this would be naturalization under Section 320 which confers US citizenship on children arriving in the USA as immigrants. American families residing abroad (civilian, military or government) should request naturalization for adopted children under Section 322 which confers US citizenship at a special swearing in ceremony during a short visit to the USA after having completed and filed form N-600K.

The August 28, 2019, USCIS Policy Alert specifies that as of October 29, 2019, military families adopting children abroad have to file for naturalization under Section 322 using form N-600K and cannot evoke their presence on a US military base abroad as constituting "US residency." They are, however, allowed to have the swearing in be done at one of the four designated overseas military bases where naturalization of service members and their family members is possible.  They do not have to travel to the US for this. This is the only difference between military and civilian naturalization procedures for children born or adopted abroad.