The stock market's been doing well and you may think it's a good time to borrow from your 401k. But financial planners say that's very risky.

Houston CPA Michael Parmet says it's never a good idea to borrow from your retirement plan.

"In my opinion it's one of the worst things they could possibly ever do."

Parmet says all sorts of things can go wrong.

"They've got 60 days to borrow money from that 401k plan and pay it back and that's not a good way to borrow money because if they don't pay it back it suddenly becomes income to them and they pay a 10% penalty."

Plus, you can be trapped in a job.

"Most companies say if you leave them you have to pay your 401k plan back immediately. So a lot of people can't change jobs because they're trapped and they can't pay it back. So it doesn't give you options."

Parmet says he tells clients to leave retirement alone and live within their means.