Roth 401K to Roth IRA rollover

I have made after-tax contributions in my workplace 401K program which I have set up to automatically transfer into a Roth 401K account in Fidelity.  I have the option of rollign over those Roth 401K funds into an IRA.  I was told first the securities have to be liquidated in the Roth 401K, then the money can be rolled over into a Roth IRA.  In my case I was planning to open a Roth IRA in Fidelity, so I wouldn't be receiving a check from Fidelity with the balance but rather they'd transfer the funds between those accounts.

 

Is there any income restriction to perform such a rollover, or any tax consequence the year of the rollover?  I'm not eligible to directly contribute to a Roth IRA.  I'm aware of the back-door Roth IRA contributions that aren't income restricted, but what I had heard about was pre-tax IRA rollovers to Roth where taxes are due for that conversion.

 

I just want to avoid any surprises, so would much appreciate it if anyone has done this and can comment to enlighten me and anyone else considering this.