Home price growth in the U.S. surged at the fastest pace in 15 years in February.

Standard & Poor’s said Tuesday that its S&P CoreLogic Case-Shiller national home price index posted a 12% annual gain in February, up from 11.2% in January. The rate is the highest year over year gain recorded by the index since February 2006. The 20-City Composite posted a 11.9% annual gain, up from 11.1% the previous month, beating consensus estimates of 11.9%, according to Bloomberg.

“Housing’s strength is reflected across all 20 cities; February’s price gains in every city are above that city’s median level, and rank in the top quartile of all reports in 18 cities,” said Craig J. Lazzara, managing director and global head of index investment strategy at S&P Dow Jones Indices, in a press statement.

Phoenix, San Diego, and Seattle continued to top the 20-City Composite. Phoenix led for the 21st straight month, posting a 17.4% annual gain, followed by San Diego and Seattle, which recorded a 17% and 15.4% annual gain, respectively.

The results were expected as median existing home prices surged to a new high of $329,100 in March, up 17.2% from the same time a year ago — rising at the fastest pace of growth since the National Association of Realtors (NAR) started tracking prices in 1999.

Real estate veteran Barbara Corcoran, founder of her namesake New York City-based residential brokerage The Corcoran Group, recently told Yahoo Finance that she couldn’t remember a time when prices have gone up at this pace.

"With national and city-composite indices, as well as all three price tiers surging at double-digit rates for the third consecutive month in February, the housing market is running full steam ahead — with many observers questioning where the train is heading and what the next stop will look like," said CoreLogic Deputy Chief Economist Selma Hepp in a press statement. "Nevertheless, while the sustainability question is reasonable, housing market strength is reflecting many of the positive and continually improving signs of the economic recovery, including employment gains, consumer savings and more purchase power among home buyers, all while mortgage rates remain historically low."

The surge in home prices has been fueled by a record shortage of homes for sale, which will not likely improve in the spring. Total housing inventory at the end of March hit 1.07 million units, up 3.9% from February’s inventory and down 28.2% from one year ago — near historic lows, according to the NAR. Unsold inventory sits at a 2.1-month supply at the current sales pace, marginally up from February’s 2.0-month supply and down from the 3.3-month supply recorded in March 2020.