The adjustment amount is pretty limited.
1st potential adjustment
If you used standard brokerage margin loans to buy anything other than private activity bonds, then you would enter no adjustments here. If your margin loans were used to purchase private activity bonds, you would enter here the amount of the interest on that portion of your loans.
2nd potential adjustment
This adjustment would occur if you used certain mortgage proceeds to purchase income-generating investments.
For AMT purposes mortgage interest is usually added back to income if the proceeds were used for any purpose other than to buy, build, or improve your home. However; if those proceeds, over and above what was used to buy, build, or improve your home, were used to make income-producing investments,you can enter that amount of interest here, and it will be allowed as a deduction for AMT.
AMT is being calculated behind the scenes at all times for your return. By the time you get to the AMT interview section, your AMT is already calculated, and you would only expect to see a change in your tax owed if you make an adjustment or enter information not already entered on your return at any earlier time.
