Part 7 of 10 Things You Must Know About Roth Accounts
If you make a conversion, you must wait five years or until you reach age 59 1/2, whichever comes first, before you can withdraw the converted amount free of the 10% penalty. Each conversion has its own five-year holding period. So if a young account owner does one conversion in 2013 and a second conversion in 2014, the amount from the first conversion can be withdrawn penalty-free starting in 2018 and the amount from the second starting in 2019.
Earnings on a converted amount can be withdrawn tax- and penalty-free after the owner reaches age 59 1/2, as long as he or she has had any Roth IRA opened at least five years.