A new poll found that more than 400,000 New Jersey families received large and unexpected medical bills over the course of a year.

Joel Cantor, director of the Rutgers Center for State Health Policy, which conducted the poll, says families in the survey said the nasty surprises came from outside and inside their health provider networks.

"For a low-income family, that could be $100. For a high income family, it might take a thousand dollar bill to be considered large," he said.

The prevalence of large and unexpected bills rose to around 1 in 5 among groups such as lower income families, those with less than a high school education, Asian, Hispanic and black residents and people who reported being in poor health.

A proposed law in the state Legislature would require health care providers to disclose when out-of-network providers serve a patient. Following a years-long debate, the Legislature in April passed the "Out-of-network Consumer Protection, Transparency, Cost Containment and Accountability Act. Gov. Phil Murphy is expected to sign it.

"Our poll suggests that while this new bill in New Jersey will address a big part of the problem, there are other parts of the problem that it will not reach. Surprise medical bills occur, even for people without insurance," Cantor said.

He says if he had to summarize the poll's finding in one word, it would be "complexity."

"This poll really just shows how complex our health care delivery and financing system is today, and the burden really on patients as well as providers and insurers to try to improve information so that people know what to expect."