The term step-family is not an old one at all. Fancher1 tells us that she at age 30 married a widower aged 32 with three children. As the first notes of the wedding march sounded, her husband to be said: “Darling girl, I’m about to make an instant mother of you.” One could say that she at the same time got an instant-family household or with today’s terminology a step-family household. As De’Ath in this volume notes, the term step-family as such did not occur in the Concise Oxford Dictionary until the middle of 1995. The first time I have seen the term used was in a book by Atme W. Simon, published in 1964. Previously there was no term for the phenomenon, only for some parts of it, like step-mother, step-father, step-child, etc. There are numerous ways of looking at what could be labelled as step-families. Since there are so many varieties and since valid data can never be found for all the varieties, I limit my presentation to numbers for just one kind of step-families: step-family households with minor children. I will further discuss the relevance of LAT (Living Apart Together) for the idea of step-families as well as the relevance of adult children and not only minors. Since most step-families are based upon remarriage, I also examine these data.