Very few 401k or 403b plans offer annuity or systematic withdrawal plans once you retire or leave the plan.  The employer plans were really designed to save money-not withdraw.  In many cases you'll have to roll the funds over to a IRA in order to create a regular income stream.  Look for some gradual changes:

Rules proposed by the Treasury and Labor departments last week will encourage more employers to offer an annuity option in 401(k)s and other retirement plans.

Visit the RetirementThink Income Annuity Basics.