An immediate annuity provides protection against outliving your assets:
Advances in technology and healthier lifestyles are allowing Americans to live longer than ever. According to the National Center for Health Statistics (1996), if you plan to retire at age 65, you can anticipate managing your assets for income 20-30 more years. But you can relax -- immediate annuity payments are guaranteed for life (or the certain period of time you choose). You can never outlive lifetime benefit payments and they will never fluctuate. With the guaranteed income offered by an immediate annuity, you'll only have to worry about managing your retirement spending.