ISO that were sold but already paid AMT tax

[ufgrad98]

A client sold some ISO's but already paid AMT tax on them in a prior year.  How do I enter the sale so that the AMT basis is correct and possibly trigger the AMT credit.

[Accountant-Man]

You need to increase the basis for the sake for AMT purposes only. There is a line for this adjustment on 6251, adjusted gain. Enter the amount as a negative.

[loricpa100]

This is the preferred method vs input a <negative preference> on the 6251 form?  Same outcome, yet with a worksheet...

[kdaglobal]

If I understood correctly, to make the cap gains adjustment for the sale of a qualifying ISO lot:

Would you go to the 6251 Wks to the Disposition of Property section and enter the adjusted net gain/loss there on the AMT line? 

TIA!

[SCV]

How to make the same adjustment  - ISO sale for which AMT taxes were paid in prior year when the stocks were exercised, for CA state taxes