According to the CoreLogic April Home Price Index (HPI) including distressed sales home prices are now up 12.1 percent on an annual basis. In March the annual increase was 10.5 percent. The April year-over-year change is the largest increase since February 2006. The HPI which excludes short sales and sales of owned real estate (REO) was up 11.9 percent in April 2013 compared to April 2012 It had risen 10.7 percent from March to March.

On a month-over-month basis the index including distressed sales increased 3.2 percent and the index excluding those sales was up 3 percent. This was the 14th straight month that the inclusive index increased nationally.

"House price growth continues to surprise to the upside with an impressive 12.1 percent gain year over year in April," said Dr. Mark Fleming, chief economist for CoreLogic. "Increasing demand for new and existing homes, coupled with low inventory, has created a virtuous cycle for price gains, most clearly seen in the Western states with year-over-year gains of 20 percent or more."

Looking ahead, CoreLogic's Pending HPI is predicting that May home prices, including distressed sales will rise 12.5 percent on an annual basis and 2.7 percent month-over-month. The Pending HPI excluding distressed sales is expected to rise 13.2 percent and 3.1 percent respectively. The Pending HPI bases its estimates on data from Multiple Listing Services.

"The pace of the housing market recovery quickened in April as home prices rose across the U.S.," said Anand Nallathambi, president and CEO of CoreLogic. "For the second consecutive month, all 50 states registered year-over-year home price gains excluding sales of distressed homes. We expect this trend to continue, bolstered by tight supplies and pent up buyer demand."

The five states with the highest annual price appreciation excluding distressed sales were Nevada (+24.6 percent), California (+19.4 percent), Arizona (+17.3 percent), Hawaii (+17 percent) and Oregon (+15.5 percent). Excluding distressed sales, the leaders were Nevada (+22.6 percent), California (+18.3 percent), Idaho (+16.4 percent), Arizona (+15.3 percent) and Washington (+13.9 percent.)

Two states lost ground on the overall index, Mississippi's prices were down 1.7 percent and Alabama's 1.6 percent. There were not states with price declines when distressed sales were excluded.

Including distressed transactions, the peak-to-current change in the national HPI (from April 2006 to April 2013) was -22.4 percent. Excluding distressed transactions, the peak-to-current change in the HPI for the same period was -16.3 percent.