Major media outlines prewrite obituaries for famous people who are old. That way, when they die, they can have the obit online in a flash. Actually, that's just a fringe benefit; the main reason is that it's much harder to get quotes and other information for the article at a time when your most likely sources are either bereaved or are deluged with requests for comment or both. One side effect of this practice is that sometimes the byline on an obituary belongs to a reporter who is also dead.
During the weekend, a large number of publications ran Jimmy Carter's de facto obituary, even though he isn't dead. He simply announced that he is terminating all medical treatment and switching to hospice mode (at home). This probably means that whatever medical conditions he has are untreatable and instead of putting him through the wringer needlessly, his doctors will just prescribe painkillers and try to keep him comfortable. You can find his obituaries at The New York Times, The Washington Post, the Los Angeles Times, CNN, the BBC, and pretty much every other media outlet that covers politics. Also, some that don't, like this digital audio Website.
Carter is 98. No other president has made it that long. Here are lists of the five presidents who died the oldest and the five who died the youngest. The ones marked with an asterisk were assassinated in office.
In short, if you want to live to be an old ex-president, it helps to: (1) be a Republican, (2) avoid being assassinated. Incidentally, in a couple of months, Joe Biden will surpass John Quincy Adams' lifespan, and in about a year he will surpass Richard Nixon's. At that point, Biden will be among the ten longest-lived presidents, even before he leaves office.
Since Carter isn't dead yet, it seems a bit inappropriate to run obituaries already, so we won't. If you want one, use one of the links above. And in case you are wondering, there are still a small number of high-ranking members of the Carter administration still among us, including Carter himself. They are: W. Michael Blumenthal (Secretary of the Treasury, now 97), Ray Marshall (Secretary of Labor, now 94), Joe Califano (Secretary of Health, Education, and Welfare, now 91), Neil Goldschmidt (Secretary of Transportation, now 82), Andrew Young (Ambassador to the United Nations, now 90), and Donald McHenry (also Ambassador to the United Nations, now 86). (V)