Limiting the tax savings from all deductions and the two major tax exclusions to 2% of an individual's adjusted gross income would reduce the deficit in 2013 by $220 billion. This 2% cap does not refer to the amounts of the deductions and exclusions but to the tax saving. This means that for someone taxed at a 25% marginal tax rate, the 2% cap would limit deductions and exclusions to 8% of that individual's adjusted gross income.
The 2% cap could also be modified to retain the existing deduction for all charitable contributions and to allow employees to exclude the first $8,000 of employer-paid health-insurance premiums from the cap. This would still reduce the current year's deficit by $141 billion. That translates to about a $2.1 trillion reduction in the national debt over the next decade.