Questions have arisen concerning whether the recently enacted health care bill imposes a new 3.8 percent Medicare tax on the net gain realized from the sale of personal residences.

The National Association of REALTORS® has described the reports as false and published an “NAR Myth Busters” circular to present its point of view. Here’s what it had to say:

“The health care bill included a provision that imposes a new 3.8 percent Medicare tax for some high-income households that have “net investment income.”

“This new tax applies only to households with an Adjusted Gross Income of more than $200,000 for individuals or more than $250,000 for married couples. Since capital gains are included in the definition of net investment income, an additional tax obligation might result from the sale of real property.

“Even if the AGI limits are met, the new tax would not be applied to capital gains that result from the sale of a home since the existing home sale capital gains exclusion rule still appliese—$250,000 (individual)/$500,000 (couple). So if the gain from the sale of the primary residence is below that amount, then NO Medicare tax will have to be paid on the gain. The new Medicare tax would apply only to a home sale gain realized in excess of the $200,000/$250,000 income limits.”

How many properties in high-priced San Francisco will be affected by the new tax remains to be seen. The good news is, the tax will not go into effect until January 1, 2013.

The U.S. housing sector received some good news Tuesday — home prices in 20 major cities rose a better-than-expected 4.2% in June on a year-on-year basis, according to the S&P/Case-Shiller U.S. National Home Price survey. Prices also rose a non-seasonally adjusted 1% in June, from May.

But June’s bright spark may represent brief relief for the troubled residential real estate sector — the data probably reflects some effects of the home buyer tax credit, an expired program that benefited residential buyers who signed contracts before the end of April. Meanwhile, reports show July existing-home sales plunged 27.2% and July new-home sales plummeted 12.4%, the latter hitting a 47-year low.

Hard-Hit Cities Improve

A Bloomberg survey had expected home prices to rise 3.6% in June on a year-over-year basis. Home prices in the 20-city index rose a non-seasonally adjusted 0.5% in May from the previous month (4.6% on a year-over-year basis) and a non-seasonally adjusted 0.4% in April (3.8% on a year-over-year basis).

Meanwhile, the 10-city index also rose a non-seasonally adjusted 1% in June (5.2% on a year-over-year basis), after rising a non-seasonally adjusted 0.5% in May (5.4% on a year-over-year basis).

David M. Blitzer, Chairman of the Index Committee at Standard & Poor’s, said June’s data was encouraging, but realtors and potential home sellers should keep in mind that the figure, like May’s and April’s data, likely still contain the effects of the home buyer tax credit.

“The monthly Composites cover June and the national index covers the second quarter, when the government’s program for first-time home buyers was winding down. While the numbers are upbeat, other more recent data on home sales and mortgages point to fewer gains ahead,” Blitzer said in a statement. “Even with concerns about near-term developments, we recognize that the housing market is in better shape than this time last year.”

“Further, California’s cities have moved from some of the hardest hit to three of the four leading cities based on year-over-year gains,” Blitzer added. “Among the other hard-hit cities, the news is also a bit encouraging.”

The home buyer tax credit, which provided an $8,000 tax credit for first-time buyers and $6,500 for repeat buyers, ended Apr. 30. Given the current mood of austerity in Washington, it doesn’t look like there’s enough political support on Capitol Hill to renew the credit again.

Key Cities Post Year-Over-Year Gains

Year-over-year percentage price changes in major U.S. cities were as follows: New York, up 0.2%; Chicago, down 0.1%; Boston, up 3.4%; Washington, D.C., up 7.3%; Atlanta, up 2%; Tampa, down 1.6%; Miami, up 1.1%; Dallas, up 1.2%; Denver, up 1.8%; Los Angeles, up 9.2%; San Francisco, up 14.3%; and Seattle, down 1.8%.

Originally greeted by Wall Street with a shrug, S&P/Case-Shiller home price data rose to market-mover status in 2008 as the housing bubble, which was fueled considerably by mortgage market excesses, finally burst.

While real estate’s doldrums are far from over, the June data does show that prices are at least not falling universally, despite inadequate job growth during the economic recovery. But tough times remain for the housing sector. Reports released earlier show July existing-home sales plunged 27.2%. And July new-home sales plummeted 12.4% — a 47-year low