WASHINGTON — About 77 million Americans have a debt in collections, a new study has found.

That amounts to 35 percent of consumers with credit files or data reported to a major credit bureau, according to a report released Tuesday by the Urban Institute and Encore Capital Group’s Consumer Credit Research Institute.

“It’s a stunning number,” said Caroline Ratcliffe, senior fellow at the Urban Institute and author of the report. “And it threads through nearly all communities.”

The report analyzed 2013 credit data from TransUnion, the credit bureau, to calculate how many Americans were falling behind on their bills. It looked at how many people had non-mortgage obligations, such as credit card charges, child-support payments and medical bills, that are so past due that the account has been closed and placed in collections.

This is the first time the Urban Institute has calculated the collections figure, but Americans may have been struggling with debt for a while: Researchers noted that the 35 percent figure is basically unchanged from when the Federal Reserve studied the issue in 2004 and found that 36.5 percent of people with credit reports had debt in collections.

The debts sent to collections ranged from $25 to more than $125,000. Many consumers were burned for relatively small amounts – about 10 percent of the debts were smaller than $125, Ratcliffe said. But the median debt, $1,350, is fairly substantial, she said.

Nevada was hit the hardest, with 47 percent of consumers with a credit file showing a debt in collections – a mark researchers said may stem from the housing crisis, when people struggling to keep up with their mortgage payments may have fallen behind on other financial obligations.

In 12 states, including the District of Columbia, more than 40 percent of residents with credit files have a bill in collections. That includes Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, New Mexico, North Carolina, South Carolina, Texas and West Virginia.

On the opposite end, Minnesota, North Dakota and South Dakota each have about 20 percent of residents with credit files with reported debt in collections.

The phrase “debt collection” normally brings to mind harassing phone calls, repeated letters and other efforts from third parties attempting to collect payment. But not all consumers get hassled: Some people may not even learn that they’ve been sent to collections until they check their credit reports, the study said.

That doesn’t mean the debts didn’t cause setbacks. Bills that are sent to collections can stay on a credit report for up to seven years, hurting a consumer’s credit score and hindering their chances of obtaining loans, credit cards and other forms of borrowing.