I generally do not work with DB plans. The document states that participants are allowed to take distributions at age 50. If the participant cashes out his account will he be subject to the additional 10% penalty? Thanks!

The 10% excise tax levied by Internal Revenue Code section 72(t) applies to both defined benefit and defined contribution plans. A lump sum distribution at age 50 would generally be subject to the 10% excise tax, absent some exception noted in section 72(t)(2). I assume by "cashes out" that you mean the person is taking a lump payment, and is not completing a direct rollover.

There is not an exception for being age 50.

There is an exception if the distribution is part of a series of substantially equal periodic payments made over the life expectancy of the employee.

Thank you for the responses!