Life expectancy changes as one gets older. By the time a child reaches their first year, their chances of living longer increase. By the time of late adulthood, ones chances of survival to a very old age are quite good. For example, although the life expectancy from birth for all people in the United States is 77.1 years, those who live to age 65 will have an average of 17.7 years left to live, making their life expectancy almost 83 years.