From factcheck.org ^[1]

^[2]Q: Does the new health care law impose a 3.8 percent tax on profits from selling your home?

A: No, with very few exceptions. The truth is that only a tiny percentage of home sellers will pay the tax. Only those with incomes over $200,000 a year ($250,000 for married couples filing jointly) will be subject to it. And even for those who have such high incomes, the tax still won’t apply to the first $250,000 on profits from the sale of a personal residence — or to the first $500,000 in the case of a married couple selling their home.

The sort of people who would have to pay the tax might include, for example:

• A single executive making $210,000 a year who sells his $300,000 ski condo for a $50,000 profit. His tax on the sale of that vacation home would amount to $1,900, in addition to the capital gains tax he would have paid anyway.
• An “empty nester” couple with combined income of over $250,000 a year who sell their $1 million primary residence to move to smaller quarters. If they cleared $600,000 on the sale, they would be taxed on $100,000 of the profit (the amount over the half-million-dollar exclusion). Their health care tax on the sale would amount to $3,800 over and above the usual capital gains levy.

Thus, for the vast majority, the 3.8 percent tax won’t apply. The Tax Foundation, in a report released April 15 ^[3], said the new tax on investment income (including real estate) “will hit approximately the top-earning two percent of families” when it takes effect in 2013.