(MONEY Magazine) – Are you healthy? If so, you may qualify for unusually low universal life or term rates. More and more life insurance companies are tinkering with the three main rate classes that partly determine the premiums that insurers charge: smoker; standard nonsmoker and preferred nonsmoker (for nonsmokers who are in good health). Last July, Midland Mutual (rated A by A.M. Best; 800-669-9100) introduced its BioEdge universal life policy that breaks nonsmokers into nine classes. Midland expects fewer than 10% of applicants will qualify for its lowest rate, though. There is another drawback: You'll have to take a medical exam every five years and, if your health worsens, your insurance premiums could rise by as much as 30%.

Federal Kemper (rated A by Best; 708-540-4500) and Manhattan National (A-; 800-767-0852) now offer preferred nonsmoker term rates, costing about a third less than standard, for two to four years even if you don't quite qualify for | preferred status. After the discount period ends, you can keep the low rate if you've achieved preferred status by, say, lowering your blood pressure. Otherwise, your premiums will increase to around the standard rate. Integon (rated A; 800-468-3466) has a term policy designed to motivate smokers to quit. It gives smokers its standard nonsmoker rate for four years plus the right to keep the discount, provided you kick the habit before the fourth year. Cost: $775 a year for a 45-year-old man's $250,000 in coverage. But remember that there is more to choosing a policy than just its rate. ''The details of the coverage and the quality of the company matter too,'' says Don Mercer, an independent agent in Alexandria, Va.