U.S. home prices jumped in January, a sign the housing market is gaining momentum as it nears the spring selling season.

CoreLogic, a real estate data provider, says home prices rose 9.7% in January from a year earlier. That's up from an 8.3% increase in December and the biggest annual gain since April 2006. Prices rose in all states except Delaware and Illinois.

Home prices also rose 0.7% in January from December. That's a solid increase given that sales usually slow over the winter months.

Sales of previously owned homes ticked up in January after rising to their highest level in five years in 2012, according to the National Association of Realtors. At the same time, inventories of homes for sale fell to a 13-year low.