Patrick Eng writes about the importance of understanding RMDs.When investors with retirement accounts turn 70 ½ years old, they should be aware of the required minimum distribution (RMD) rules regarding the type of retirement accounts they possess. Understanding RMDs will help you avoid high penalties from the IRS. Here are some things to keep in mind.

The IRS requires that account holders of traditional IRA, SEP IRA, Simple IRA and company-defined contribution plans [401(k), 403(b) and 457] withdraw a certain minimum amount from their accounts each year. (Roth IRAs do not have an RMD.) If you continue working past 70 ½ years, many defined contribution plans will allow you to put off taking the RMD until you retire; but for all non-Roth IRAs, you have to start taking RMDs by April 1 of the year following the year in which you turn 70 ½, even if you are still working.

This is an annual requirement until the account is drawn to zero or until the account holder dies, in which case the assets can be placed into an Inherited IRA for a beneficiary or distributed to heirs in another way. A penalty of 50 percent is levied by the IRS on the amount not withdrawn. For example, if your RMD is $10,000 and you do not make your withdrawal, you will owe the IRS $5,000 in penalties and must still take your required distribution.

The IRS does not allow tax-deferred accounts to grow indefinitely without having to pay taxes on the money. Investments in a tax-deferred retirement account have been sheltered from taxes since their initial contribution and throughout the accumulation and investment period. Thus, the IRS places a time limit on this tax deferral and mandates withdrawals through the RMD.

Most financial institutions have a process to help their clients take care of their RMDs, but ultimately the responsibility lies with the account holder. It can be an expensive oversight if not taken care of in a timely manner. If you are approaching the age for RMDs, talk with your advisor.