Home price increases in Massachusetts, where the median sale price is approaching $400,000, are spurring debate about affordability and how high prices can go before there’s a downturn. Index results released Tuesday show the same conversations may be happening in other parts of the country.

Home prices continued to rise across the country over the past 12 months and the index, which covers all nine U.S. census divisions, reported a 5.8 percent gain in June, up from 5.7 percent in May. Seattle experienced a 13.4 percent price increase in June, followed by Portland, Oregon and Dallas, Texas at 8.2 percent and 7.7 percent respectively.

Boston-area home prices were up 6.2 percent, according to the S&P CoreLogic Case-Shiller U.S. National Home Price NSA Index.

“Price increases are supported by a tight housing market. Both the number of homes for sale and the number of days a house is on the market have declined for four to five years,” David Blitzer, managing director at S&P Dow Jones Indices, said in a statement. “Currently the months-supply of existing homes for sale is low, at 4.2 months. In addition, housing starts remain below their pre-financial crisis peak as new home sales have not recovered as fast as existing home sales.”

While higher prices affect affordability, Blitzer noted that U.S. jobs continue to grow “at a robust pace, rising to close to 200,000 per month,” with wages and salaries nationally increasing “a bit ahead of inflation” and mortgage interest rates up but still below 4 percent.

“Given current economic conditions and the tight housing market, an immediate reversal in home price trends appears unlikely,” Blitzer said. – Michael P. Norton/SHNS