Final answer:
In the United States, people aged sixty-five and older are typically considered senior citizens, and this is when they become eligible for federal benefits like Social Security and Medicare.
Step-by-step explanation:
In the United States, people aged sixty-five and older are typically considered senior citizens.
This age is commonly accepted as the definition of being elderly by the U.S. government, which is when citizens become eligible for federal benefits such as Social Security and Medicare.
The older adult population can be further divided into three subgroups: the young-old (approximately sixty-five to seventy-four years old), the middle-old (ages seventy-five to eighty-four), and the old-old (over age eighty-five).