If you have not met another triggering event and your withdrawal is from a traditional 403(b) or a traditional 457 account you will be subject to State and Federal income tax and a 10% early withdrawal penalty. If you have met another triggering event, such as age, you would not normally be subject to the early withdrawal penalty.
A Roth distribution would not normally be subject to income tax, however it may be subject to an early withdrawal penalty if the distribution is taken before the account has been held for five years.