They are asking for line 28 of Form 6251 but I don't see a form 6251 from last year...what value should I enter

[MarilynG]

Form 6251 is for Alternative Minimum Tax (AMT).  If you did not pay AMT last year, you could enter $0 or leave the field blank.

Here's more info:

https://ttlc.intuit.com/replies/3299960

[JayKepps]

Maybe a better solution would be for them to fix their screwed up program.  If it's look at a turbo filing from the previous year, the software should recognize when a user did NOT file AMT and it shouldn't even ask this confusing question.