Home sales dropped from an upwardly revised annual rate of 325,000 on an annual basis in December to 284,000, dropping 12.6 percent in the month.
January's sales came in 18.6 percent lower than January 2010, when the annual rate stood at 349,000.
The Commerce Department said the median sales price for a new home sold in January fell from $241,500 a month earlier to $230,600.
At the end of January, there were 188,000 homes on the market, a 7.9-month supply at the current rate of sales.
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