So what is "Old?"  The answer among Americans varies from various age groups. According to a new Marist survey,  the age of 73 is considered old by Americans, but Baby Boomers say "old age" doesn't begin until age 77.   Americans in "Generation X" (people born from the early 1960s through the early 1980s) say old age arrives at age 71.  When asked in the poll what age they hoped to live to, all respondents said at least until 90.