As with most kinds of personal insurance, the younger you are when you purchase long-term care insurance, the lower your premiums will be. Once you own a policy, premiums generally don't increase with age, unless an insurance company raises them for a whole class of policyholders.

When you consider that 40 percent of those receiving long-term care are under age 65, you should at least give some thought to buying coverage when you're still relatively young. Doing so should allow you to lock in a low rate while providing you with coverage that may be needed sooner than you think. Also, be aware that most companies won't sell individual policies to people under age 18 or over age 84.

If you can't buy as much coverage as you think you need, consider buying an affordable plan now and enhancing it later when your financial situation improves.