Prices in a measure of 20 cities increased 7.4% from a year earlier, larger than the 7.3% annual gain in February, an S&P CoreLogic Case-Shiller index shows.

Homebuyers are facing a severe affordability crisis made worse by mortgage rates hovering around 7% and price growth that's only accelerating. At the heart of the problem is the lack of previously owned homes for sale: Few owners are willing to move if it means letting go of a loan locked in when rates were cheap. While listings have increased in recent months, inventory still remains historically tight.

San Diego posted the biggest annual gain among the 20 cities, followed by New York and Cleveland. The Northeast is the "top performer," according to Brian Luke, head of commodities, real and digital assets at S&P Dow Jones Indices. 

"COVID was a boon for Sunbelt markets, but the bigger gains the last couple of years have been the northern metro cities," Luke said in a statement.