If you're happy with your former 401(k), you can leave your account where it is.
You can elect to roll over your traditional 401(k) into a traditional IRA.
“Many Americans have old 401(k) plans, which may not be properly positioned to help them prepare for retirement."
- From Take Charge of Your 401(k)
If you switched jobs or are preparing to, download your complimentary ebook to help you decide what to do with your 401(k).
Free Portfolio Risk Analysis