Home prices moved up as a result of last-minute home buying activity before the expiration of the federal home buyer tax credit on April 30, according to the S&P/Case-Shiller Home Price Indices for April.

The indices, released Tuesday, showed a 4.6% rise in the 10-City Composite Index and a 3.8% increase in the 20-City Composite in April compared to the same month a year before. On a month-to-month comparison, 18 of the 20 MSAs and both Composites rose sequentially March, with the 10-City up 0.7% and the 20-City up 0.8%.

"The month-over-month figures were driven by the end of the federal first-time home buyer tax credit program on April 30th," said David M. Blitzer, chairman of the index committee at S&P. "The April 2010 data for all 20 MSAs and the two Composites do show some improvement with higher annual increases than in March's report. However, many of the gains are modest and somewhat concentrated in California. Moreover, nine of the 20 cities reached new lows at some time since the beginning of this year. "

"Other housing data confirm the large impact, and likely near-future pullback, of the federal program," Blitzer continued. "Recently released data for May 2010 show sharp declines in existing and new home sales and housing starts. Inventory data and foreclosure activity have not shown any signs of improvement. Consistent and sustained boosts to economic growth from housing may have to wait to next year. "

Prices on average, nationally, were back to late-summer/early fall 2003 levels at April's end. From their peak in June/July of 2006 through the trough in April 2009, the 10-City Composite is down 33.5% and the 20-City Composite is down 32.6%. Peak-to-date through April 2010, the Composites are down -30.5% and -30.0%, respectively.

The biggest gainers month-over-month were Washington D.C. (+2.4%), San Francisco (+2.2%) and Dallas (+2.0%). Three markets posted gains of 1.8%, including Atlanta, Minneapolis and Portland. Denver clocked in at a 1.7% gain., Cleveland and Boston at a +1.4%, Charlotte at a +1.1% and Seattle at a +1.0%. The rest of the March-to-April gainers were up less than 1%.

Miami (-0.8%) and New York (-0.3%) were the only markets to post sequential declines. New York posted a new index low in April of 168.95, as measured by the current housing cycle, where it peaked in June 2006. Peak-to-trough, New York is down 21.7%, with prices up approximately 69% from the base month of January, 2000.

Home price levels remain close to the April 2009 lows set by the 10- and 20-City Composite series.

Year-over-year, the April results were more mixed. San Francisco and San Diego continued strong recovery, up 18% and 11.7%, to indices of 139.77 and 161.39, respectively. The next nearest gainer was Minneapolis, up 9.5% year-over-year, but its index is at 118.89. Washington was up 7.3% over April, 2009 and boasts the highest value retention of all markets with an index of 179.49. Los Angeles was up 7.8% year-over-year with an index of 171.78. Cleveland rose 6.8% to 104.77. Phoenix managed a 5.4% gain to 110.06. Boston was up 4.9% to 153.56; Denver was up 4.4% to 118.14. Among other gainers were Dallas, up 3.3% to 118.14, and Atlanta, up marginally(0.2%) to 105.64.

Las Vegas continued to lead markets with losses, down 8.5% year-over-year to an index of 102.82. Detroit lost another 3% to an index of 67.81. Seattle was down 2.8% to 145.15; Tampa dropped 2.4% to 137.09; Charlotte fell 2.2% to 116.05; Chicago declined 1.6% to 120.43; New York lost 1% to 168.95; Miami was down 0.5% to 145.04 and Portland dropped 0.4% to 146.25.

Learn more about markets featured in this article: Los Angeles, CA.