Required minimum distributions are the amounts that you must withdraw each year from your traditional IRA, employer-sponsored retirement plan, or tax-sheltered annuity. You must begin to take the annual distributions by April 1 of the year following the year in which you reach age 70½. This is known as your required beginning date. If you work for your employer past age 70½ and are still participating in the employer's retirement plan, you may postpone your first distribution from that plan until April 1 of the year following the year of your retirement (as long as you are not more than a 5 percent owner of the employer).

Note: The Worker, Retiree and Employer Recovery Act of 2008 waives required minimum distributions for the 2009 calendar year.

Regardless of your required beginning date, you must take subsequent distributions by December 31 of each calendar year. You'll continue to take the annual distributions each year until your death or until your account balance is reduced to zero. You can always withdraw more than the required minimum amount in any given year. However, if you withdraw less, you will be subject to a 50 percent federal penalty on the difference between the amount you should have taken and what you actually took.

The basic calculation for individual accounts provides that the required minimum distribution is determined by dividing the account balance by the distribution period. For lifetime required minimum distributions, there is a uniform distribution period for almost all individuals of the same age. The uniform lifetime distribution period table is based on the joint life and last survivor life expectancy of you and a hypothetical beneficiary 10 years younger. However, if your sole beneficiary is your spouse and he or she is more than 10 years younger than you, a longer distribution period measured by the joint life and last survivor life expectancy of you and your spouse is permitted to be used.

However, the specific rules on required minimum distribution calculations are complicated, and you should consult a tax professional regarding your situation.