You are either lying, committing tax fraud, omitting information or miscounting your total tax burden.
The effective Federal Income Tax before any deductions on $120,000 annual salary is 23%
From here: http://www.irs.gov/formspubs/article/0,,id=164272,00.html
Your tax burden would be $15,698.75 + 28% * ($120,000 - $77,100) = $27,710.75.
The D.C. tax schedule shown here: Bankrate: Guiding you through life's financial journey
Gives us a state tax burden of $10,000 * .04 + $30,000 * .06 + $80,000 * .085 = $9,000.
Your Social Security Tax would be 6.2% of $94,200 = $5,840.40
Your Medicare Tax would be 1.45% of $120,000 = $1,740
**This is a total tax burden of $44,291.15. That is a tax rate 36.9%. **
You claim to be paying $28,800 in taxes. In order for you to have enough deductions to bring your Federal Income Tax to the $12,219.60 that you are claiming you would have to have $56,800 in deductions to get your AGI to $63,200.
If you own a home you would be adding Property Tax onto that amount at 0.85% of the value of the home. With a Median Condo value in DC of $397,000 that would be a median Property Tax of $3,374.50 or an additional 2.8% of your Income.
If you buy things you will be adding a Sales Tax ranging from 5.75% to 14.5% of the purchase price depending on what you are buying in DC. Let’s consider you to be a extremely frugal shut-in and your consumer expenditures to be $50,000 and the average sales tax of about 7% which means you’ll be adding an additional $3,500 in taxes per year or about 3% of your Income. Go here if you want to find the averages in more detail and break out the tax rates by segment.
I think you should think twice before questioning anyone’s math.