There have been calls from both parties to reform the individual tax code to increase economic efficiency and reduce the cost of preparing taxes—which has been estimated as hudreds of billions of dollars.

Most reformers generally find that a flatter tax code accomplishes both goals. It reduces the economic inefficiencies of high marginal rates, and distortive deductions and credits (which are merely spending by another name); they also make filing a tax return much easier. But few realize that a version of this tax code already exists: it’s called the Alternative Minimum Tax.

The AMT was instituted in 1969 because of a fear that wealthy Americans were successfully evading tax through the use of deductions and credits (sound familiar?). The AMT is a flatter tax, with rates of 26% and 28%, with an exemption of around $50,000, and has very few deductions. Individuals have to pay either regular tax or the AMT, whichever is greater.

The AMT has very few political supporters because of its current role in the tax system. For one, the AMT can only ever increase your tax burden. Second, the AMT does add complexity to the tax code, but only through its integration with the regular tax system. To formally calculate your AMT on IRS forms, for instance, you have to add back in most of the deductions that you subtracted in a previous step.

Instead of attacking the AMT, politicians should instead embrace it as a model for what the entire individual tax code should be, at least conceptually: a flat tax with a high exemption and few deductions. Of course we would need to make some changes to the AMT if we wanted it to replace the current income tax: we would want to lower the exemption significantly (say, to $15,000) and create two rate levels (say, 20% and 30%).

Note that this would still be a very progressive tax. Imagine a $15,000 exemption; income up to $40,000 is taxed at 20% and income above $40,000 is taxed at 30%. Take a look at the table below:

The average tax rate increases from 5% for if you make $20,000 per year to 29.3% if you make $1 million per year. And keep in mind that most deductions—which would be eliminated by a flatter tax—mostly favor the wealthy, making this system more progressive by comparison.

Thus, while the AMT isn’t perfect, it can be an inspiration to create a flatter and fairer tax code.