The minimum distributions table for individual retirement accounts is posted on the website for the Internal Revenue Service. Failure to withdraw the required amounts can result in a 50 percent excise tax on the amount that was not distributed, explains the IRS.
The minimum distribution amount that must be withdrawn in a given year is calculated by dividing the ending account balance from the preceding year by the distribution period that is found on the uniform life table, notes the IRS.
The first withdrawal generally begins on April 1 following the calendar year that the individual reaches 70 1/2 years of age or retires, according to the IRS. Following this initial date, all subsequent distribution withdrawals are required by Dec. 31.