I notice there are self selected PIN numbers from prior years in the supporting documents. Is it ok just to use the AGI from 2017 for efiling this year?

[fanfare]

congratulations, most persons posting here never seem to find the PIN from last year or know anything about it.

[fanfare]

your self-selected PIN will come in handy if you suffer from the AGI mismatch REJECTED message.

Either one can be used to e-File

I have no idea why TurboTax is saying that five-digit PIN would not work.

you can select  a new PIN or the same PIN each year, for next year.

[Cindy0H]

Yes, it is. The self-selecting PIN numbers are not being used this year. The IRS is asking for your last year's Adjusted Gross Income (AGI) in lieu of that PIN number.