For the estimated million-plus folks who turned 70 1/2 years old last year, time is running out to take their first required minimum distribution from their various 401(k) and IRA accounts without incurring stiff tax liabilities.

Kevin Walsh, Fidelity Investments' vice president of product management, says his firm has been busy this week reminding financial advisors to take a good look at their retirement client accounts to make sure people who may have been confused by recent changes in the RMD requirement are aware they have until April 1 to take their distribution.

"From our perspective, it's one last time to remind advisors who are working with retirement clients to meet the RMD," he said. "Otherwise, there are significant consequences for not meeting the deadline."

Those obligated to take an RMD and fail to do so by the close of business April 1 will be subject to a 50% tax rate on the total amount that should have been distributed. The IRS uses a formula based on the total value of retirement assets and the investor's life expectancy to determine the RMD. While there are considerable variations, a typical retiree who turned 70 1/2 in 2010 with $1 million in IRA would have to take a $38,000 RMD or else face a tax bill of $19,000.

While this has been standard practice for years, things changed briefly in 2009 when the Worker, Retiree and Employment Recovery Act of 2008 temporarily suspended RMDs for IRAs and defined contribution plans during 2009.

Although WRERA eliminated RMDs for many clients in 2009, it left other aspects of the law unchanged and created some level of confusion for investors who were given a pass in 2009 but turned 70 1/2 in the interim.

"This uncertainty and confusion combined with the stiff penalty are the two main reasons we're going back to folks to make sure they're aware of this and are taking the RMDs when required," Walsh said, adding that roughly 12% of Fidelity's IRA customers turned 70 and 1/2 years old in 2010.

Fidelity has also developed an RMD calculator and other materials pertaining to RMD rules and regulations for advisors and clients who want to protect themselves from unnecessary and exorbitant taxes and penalties.

"It's just a friendly reminder," Walsh said. "For some clients and their advisors, this is new as they've reached the age of 70 and 1/2 years and are now switching to the RMD phase."