I recently joined my 401 k plan at work and rolled over money from a previous employer's 401 k plan. I need to do a hardhsip withdrawal for my son's college expenses and they are telling me I am not allowed to take a hardship withdrawal on rolled over monies, they say it is in the plan description which I was not aware of or I would have never rolled over the money. Please help I am desperate, is there anything I can do?

Can you take a loan against the balance. That would be better than taking a withdrawal anyway.

I will explore every possible option before I access this money but need to know I can if it is necessary. My credit is mediocre at best credit score only 650 and may be denied loans or even qualify as a cosigner for a student loan

First, if the plan does not allow you withdraw rolloever funds, then you can't, end of that story.

A 401K loan is not subject to a credit check. The interest that is charged on the loan goes right back into your account. You are borrowing from yourself and paying yourself interest.

If you withdraw the money you will lose 35-40% in taxes and penalties.

bosco1 - even if your employer would allow a withdrawal (and most plans do not, at least not for active employees) you would have to pay both income tax and the 10% early withdrawal penalty on it. If you had known that you were going to need this money for your son's college expenses you should have rolled it from your old employer's 401(k) to your own rollover IRA. This would have (a) allowed you to take the withdrawal when you want, and (b) avoided the 10% early withdrawal penalty. At this point the best plan is to see about taking a loan from your 401(k), which as ScottGem says is better than taking a withdrawal anyway.