Not a tax question?
In general, if you leave a company, you can leave your funds in their 401k if they will allow it. It depends on how the plan is written and there may be a minimum.
If the plan requires you to leave after separating from service, you can rollover the funds into a private IRA that you can open at most banks or brokers. It's best to do this electronically between the 401k and the IRA without you touching the money in between. Pick a broker, open an IRA, and then tell them you want to do a rollover from a former 401k.
You may also be able to rollover the funds to the retirement plan at your new employer, ask them first.
If you simply withdraw the money, you will be subject to income tax on the entire amount, plus a 10% penalty if you are under age 59-1/2 (but there is no penalty if you were 55 or older when you left your employment with the company).
