Rising home prices and a slim supply of starter homes in many areas are making this spring a challenging one for first-time buyers, real estate professionals say.

The typical price of a previously owned home in March was about $250,000, up nearly 6 percent from a year earlier, according to the National Association of Realtors. The median price was higher in certain parts of the country, particularly in the Northeast and the West.

And, homes sell quickly when they come on the market — especially smaller, lower-priced homes. Seasonal demand is increasing as usual, but buyers are finding that there is a lack of new listings. Homes are going under contract in about a month, the association reported, about four days faster than last year.

“The starter house is nearly missing in some markets,” said Jessica Lautz, the association’s managing director of survey research and communication.