More than 200,000 people in the United States were unclaimed on Friday, according to the National Association of Realtors.
The association said the figure could be higher as many of those who lost money have not filed the correct tax returns.
The NAR’s data showed the U.S. is the only advanced economy where more than one-quarter of unclaimed property is unclaimed.
It said the trend was driven in part by a spike in unclaimed homes during the 2008 housing bubble.
The data shows that the vast majority of uncollected property is in the San Francisco Bay Area, which has a high concentration of unincorporated areas and is home to more than 300,000 unincarcerated people.
The housing market has been in the news recently because of a massive housing bubble that was triggered by the 2008 financial crisis.
That led to an increase in foreclosures, which resulted in millions of dollars in lost property taxes.