WASHINGTON (AP) — U.S. home prices continued to rise at a steady pace in January, as the housing market deals with affordability problems and few properties listed for sale.

The Standard & Poor’s/Case-Shiller 20-city home price index rose 4.6 percent in January compared with 12 months earlier, S&P said Tuesday. That is up from growth of 4.4 percent in December.

Few Americans have listed their homes for sale, with the tight inventory keeping prices higher. Robust hiring and low mortgage rates have raised the possibility of stronger sales, yet home prices have appreciated at a significantly faster pace than earnings.

“Home prices are rising roughly twice as fast as wages, putting pressure on potential homebuyers and heightening the risk that any uptick in interest rates could be a major setback,” said David Blitzer, chairman of the index committee for S&P Dow Jones Indices

The Case-Shiller index covers roughly half of U.S. homes. The index measures prices compared with those in January 2000 and creates a three-month moving average.

Housing inventories have been tight since December. The number of homes for sale in February was equal to just 4.6 months of sales, compared to an average of 5.2 months last year. Six months of supply is typical for a healthy housing market.

All 20 cities reported higher prices than a year earlier. Denver reported the largest gains, with prices up 8.4 percent.

Miami prices jumped by 8.3 percent, while Dallas homes appreciated at 8.1 percent. Home appreciation nearly plateaued in Washington, D.C., where prices rose just 1.3 percent.

Signed contracts in February suggest that sales will rebound after a sluggish start to 2015.