The most basic answer is the same as with any sort of insurance policy. It depends on how "risk averse" you are, as economists would say. Some gamblers never buy insurance for anything. Some conservative people insure everything.

Long term care insurance is most popular among older people, especially the aging Baby Boomer generation. Elderly are the most likely to need it. However, the U.S. government estimates that 40% of the 13 million people receiving long term care are between 18 and 64. Part of the reason that number is so high is that it includes handicaps of all types. But an accident can happen to anyone.

Also, note that the sooner you get long term care insurance, the less it will cost. The premiums generally don't increase as you age.