Generally, a rollover is a tax-free distribution to the taxpayer from one retirement account (traditional IRA or employer's pension plan) that rolls over into a similar retirement account within 60 days.
Form 1099-R will be issued to the taxpayer by the financial institution. If it was a direct rollover by the institution to another institution, box 7 will contain code G. If there is no code G, ask the taxpayer if the full amount was redeposited into an appropriate account within 60 days. If it was not, the distribution may be partially or fully taxable; refer the taxpayer to a professional tax preparer.
Starting in 2015, there is a limit of one IRA rollover per year. This does not affect the ability of an IRA owner to transfer funds from one IRA trustee directly to another because such a transfer is not a rollover.