18 Years Worth of Days The average retirement lasts for 18 years. Are you prepared to fill that many days? Share | Related Content The Power of Tax-Deferred Growth Why are 401(k) plans, annuities, and IRAs so popular? Systematic Withdrawals in Retirement Taking regular, periodic withdrawals during retirement can be quite problematic. Retirement Plan Distributions There are a number of ways to withdraw money from a qualified retirement plan.