The cheapest rates, known in the business as select or preferred, go to those who are in good health and who have a family history of good health. If you take heart medication or are grossly overweight, you'll pay 50 percent more than preferred rates.

If you smoke, have a poor driving record, or engage in risky sports like skydiving, you'll pay even more for life insurance. Rates can be four times more than the preferred rate.

If you fall into one of these more expensive categories, it pays to shop around. One company may charge much more than another, depending on how it estimates the risk of your condition (that's called underwriting). This is where a knowledgeable agent may come in very handy. Internet and phone quote services aren't set up to deal with nonstandard policies.

Why, some people might ask, should I tell the insurance company about negative information that will raise my rates? Well, even if you somehow get around the medical tests and other checks done before the policy is issued, you're just kidding yourself.

Insurers seldom pay out large claims without doing some checking. If the company finds out you've lied, the claim may be denied, or your heirs could be tied up in court for years.

So there's a good case to be made for getting a policy early in life while you are still in good health. However, it doesn't make much sense to buy one until you have dependents.