While not general to all Americans, there's a minority subset of couples who do not combine household expenses. There's a bunch of reasons for this: if you are

While not general to all Americans, there's a minority subset of couples who do not combine household expenses. There's a bunch of reasons for this: if you are divorced, it can simplify some of the processes around alimony. If you had a bad relationship due to finances in the past, some people prefer financial independence, or if the couple have other complications that makes combining household finances complicated (like trusts, or property owned with a different party).