Only if you're 59 1/2 or older. Depending on your 401(k) plan's rules, you can take a loan out for which you'd have to pay interest and have to repay in a certain time frame, or you can take a hardship withdrawal, which will be taxed at your regular income tax rate plus a 10% penalty rate. You should check out your plan's documentation to see what your options are, and you can read more about it here: http://www.filife.com/stories/cashing-out