I forgot my pin 5 digit pin to e-file. how do i retrieve it. I'm also not talking about the 6 digit irs pin.

[Critter]

You only need the 2017 AGI  OR  the PIN ... you do not need both. 

[fanfare]

leave the AGI field empty, and proceed.

if turbotax has your PIN, it should appear.

NOTE: I'm guessing; that's how other programs do it.