WASHINGTON – The housing market is flashing signs of health ahead of the spring-buying season.

Sales of previously occupied homes are at their highest level since May 2010. More first-time buyers are making purchases. And the supply of homes fell last month to its lowest point in nearly seven years, which could push home prices higher.

Sales have now risen nearly 13 percent over the past six months. While they are still well below the 6 million that economists equate with a healthy market, the gains have coincided with other changes in the market that suggest more sales are coming.

“The trend is clearly upward,” said Ian Shepherdson, chief U.S. economist at High Frequency Economics.

The National Association of Realtors said resales increased 4.3 percent last month to a seasonally adjusted annual rate of 4.57 million.

Single-family home sales rose 3.8 percent. And the number of first-time buyers, who are critical to a housing recovery, increased slightly to make up 33 percent of all sales. That’s still below 40 percent, which tends to signal a healthy market.

One concern is the market is still saturated with homes at risk of foreclosure, which lower broader home prices. Those increased to make up 35 percent of sales.

But the supply of homes on the market has plunged to 2.3 million, the lowest level since March 2005. At last month’s sales pace, it would take more than six months to clear those homes, consistent with a healthy housing market. Fewer homes on the market could help boost prices over time.

Most economists said the January report was encouraging, especially when viewed with other recent positive housing data.

Mortgage rates have never been lower. Homebuilders are slightly more hopeful because more people are saying they might be open to buying this year – and they responded in January to that interest by requesting more permits to construct single-family homes.