Unless you're age 59 1/2 at the time of the disribution, you'll be liable for a 10% penalty. There are a number of exceptions to the penalty. The most common ones (there are others and read the fine print before acting) that you may qualify for:
* distrubutions to pay deductible medical expenses
* amounts to pay qualifying medical insurance premiums to cetain unemployed individuals
* qualified higher education expenses for you, your spouse, children, or grandchildrenm and
* up to $10,000 for first time homebuyer expenses for a principal residence.
Form 5329 http://www.irs.gov/pub/irs-pdf/f5329.pdf
Form 5329 Instructions ( See Exceptions - Bottom of Page 2 and top of Page 3) http://www.irs.gov/pub/irs-pdf/i5329.pdf