AMT Credit question (and my answer :))

[HS2]

I have credit from prior year(s) which TT picks up fine (thank you!). Quick question:

As I play around with it by adding a dummy stock sale, it doesn't seem to offset tax penalty 1:1 after a certain point. Example, I have more AMT tax credit from prior years than tax due but it maxes the credit out at a certain point. Is that true?

Edited and based on what I find in Form 6251:

There is an upper limit and it appears to be $126.5K for MFJ, different for other filers and then a plethora of number crunching which spins your head to arrive at the conclusion which I wish wasn't true. Alas!

Feel free to comment.

Thank you all.

[AmyC]

Yes, AMT has an exemption amount that is set based on filing status and a phaseout of the exemption based on income.

From Topic No. 556 Alternative Minimum Tax - IRS:

The AMT is the excess of the tentative minimum tax over the regular tax. Thus, the AMT is owed only if the tentative minimum tax for the year is greater than the regular tax for that year. The tentative minimum tax is figured separately from the regular tax. In general, compute the tentative minimum tax by:

1. Computing taxable income eliminating or reducing certain exclusions and deductions, and taking into account differences with respect to when certain items are used to compute regular taxable income and alternative minimum taxable income (AMTI),
2. Subtracting the AMT exemption amount,
3. Multiplying the amount computed in (2) by the appropriate AMT tax rates, and
4. Subtracting the AMT foreign tax credit.

The law sets the AMT exemption amounts and AMT tax rates. Taxpayers can use the special capital gain rates in effect for the regular tax if they're lower than the AMT tax rates that would otherwise apply. In addition, some tax credits that reduce regular tax liability don't reduce AMT tax liability.