The rules from the IRS state the paragraph below....I am assuming that beginning it before 2010 ......then moving it to another company doesn't require you to start the 5 years all over again.....
What Are Qualified Distributions?
A qualified distribution is any payment or distribution from your Roth IRA that meets the following requirements.
It is made after the 5-year period beginning with the first taxable year for which a contribution was made to a Roth IRA set up for your benefit, and
The payment or distribution is:
Made on or after the date you reach age 59½,
Made because you are disabled (defined earlier),
Made to a beneficiary or to your estate after your death, or
One that meets the requirements listed under First home under Exceptions in chapter 1 (up to a $10,000 lifetime limit).