The IRS has updated its online alternative minimum tax (AMT) calculator. (IRS News Release IR- 2007-18) Using the online tool, you can determine your AMT liability in five to 10 minutes. It’s an automated version of the work sheet used to fill out Form 6251.
You can find the “AMT Assistant” at www.irs.gov/businesses/small/article/0,,id=150703,00.html. There’s one drawback: If you have certain tax-preference items—such as accelerated depreciation or tax-exempt interest from private-activity municipal bonds—the IRS still requires you to fill out Form 6251.