The report found that more than 46 million people are considered poor. The overall poverty rate climbed to 15.1 percent from 14.3 percent the previous year. For a family of four, that's a household income of less than $22,300 a year.
In California, it's even higher. More than 16 percent of the population is poor, the highest level in 13 years.
The median household income in the state fell nearly $300,000 to just over $54,400. In the U.S., the median household income was $49,445, down 2.3 percent from 2009.
The percentage of Americans without health coverage rose to 16.3 percent, or about 50 million people.
Congress passed a health overhaul last year to address rising numbers of the uninsured. While the main provisions don't take effect until 2014, one aspect taking effect in late 2010 allowed young adults to be covered under their parents' health insurance until age 26.
The uninsured rate for adults 18 to 24 actually declined last year, from 29.3 percent to 27.2 percent, noted Brett O'Hara, chief of the Health and Disability Statistics branch at the Census Bureau. That was the only age group that posted a decrease, and he said " the law change certainly could be a factor."
The Census Bureau report, released Tuesday, offers a somber snapshot of the economic well-being of U.S. households.
The Associated Press contributed to this report.