It's often best to initiate the transfer at the receiving IRA custodian rather than the original IRA custodian. Doing so tends to make it more clear to both the receiving custodian and the original custodian that the transaction is a nonreportable trustee-to-trustee transfer and not a reportable distribution and rollover. It also helps ensure that the funds end up in the right kind of account upon completion of the transfer.
Even if done as a distribution and rollover it would not be taxable (unless it was a violation of the one-rollover-per-12-months limitation, in which case it would be a failed rollover and excess contribution). The reason to do it as a nonreportable trustee-to-trustee transfer is to avoid any involvement of the one-rollover-per-12-months limitation. A trustee-to-trustee transfer is also the only permissible way to move some or all of an inherited IRA to another inherited IRA.
