A tax-free, non-reportable movement of assets between retirement plans. Generally, transfers occur between similar types of plans: for instance, from a Roth IRA to a Roth IRA. There is no limit on the number of transfers that may occur between retirement plans, but a transfer must occur between the trustees/custodians of the retirement accounts. This means that the assets are made payable to the trustee/custodian, not to the retirement account holder.