Penalties for Failing to Take Required Distributions
Beginning in the year that you turn 70 and 1/2, you must start taking required minimum distributions from your qualified retirement plans. You can postpone required minimum distributions from 401k and 403b plans if you’re still working, as long as you don’t own more than 5 percent of the company in question.
If you fail to take the required withdrawal, the IRS imposes a penalty equal to 50 percent of the amount you didn’t take out.