New data from the U.S. Census Bureau show people who use public benefits generally get help for at most a couple of years.
The report, released Thursday, looked at major federal safety net programs.
Researchers found that over a four-year period, 79 percent of people who received cash General Assistance - known as "welfare" - left the program within two years. About half left supplemental security income, medicaid, and food stamps in the same amount of time.
The major outlier was housing assistance - including public housing and subsidized rental programs. There, only 40 percent dropped out within two years.
Experts said the numbers confirmed what they've been noticing for years.
"I think there's a myth out there that there's a swath of the public that simply doesn't work and they linger on welfare benefits for their entire adult lives - and that's just not the case," said UC-Irvine Law Professor Kaaryn Gustafson.
UCLA Law Professor Noah Zatz said many of these programs function as a sort of unemployment insurance for those who don't qualify.
"Unemployment tends to require a long work history, so those who are temporary or part-time workers tend not to qualify" to receive unemployment benefits when they lose a job, he said. "Or you may not be eligible if you move because of family obligations and lose your job that way."
For him, the numbers also show how difficult it's become to access some of these programs because of eligibility requirements and time limits.
"The tenant program, general assistance, those are the most stigmatized programs," he said. "This just reflects the extent to which the programs for those who are in the most economic distress have been hammered."
Gustafson said some people do linger for years and years in the system. Those tend to be the neediest and hardest to employ: people with disabilities, seniors, mothers caring for small children, and people who care for disabled or elderly relatives.