if your adjusted gross income is over $200,000 ($250,000 married filing jointly)
it's also 0.9% on earned income.
so if you're in the top bracket due solely to earned income, the rate would be 40.5%.
but if 100% of your income were unearned (dividends, interest, etc.) the rate would be 43.4%.
actual mix would be somewhere in-between, so it could be 42% if the mix is right.
http://www.bbdcpa.com/articles/tax-provisions-in-new-patient-protection-and-affordable-care-act/