WASHINGTON — The number of people living in America without medical insurance rose 2.9% to a record 46.6 million in 2005 as health-care costs climbed.

The share of those living in poverty was unchanged at 12.6%, and the median household income rose for the first time since 1999, the Census Bureau said yesterday.The American economy expanded 3.2% and added 2-million jobs in 2005.

Republicans and Democrats in Washington have failed to find solutions to soaring medical expenses, which rose three times as fast as wages last year alone, researchers say. Last year marked the fifth straight increase in the number who lack health benefits. States such as Massachusetts are working out their own plans to get more people insurance.

“There is not any bipartisan vision from Washington for how you would cover a substantial number of people,” a professor of policy at the Harvard School of Public Health, Robert Blendon, said. “The parties are so far apart that they can’t even talk about how to move this thing ahead.”

The number of people lacking health insurance rose even with a 1.1% gain in median household income to $46,326 last year, the Census Bureau said. Incomes rose 2.9% in the Northeast and 1.5% in the West and were unchanged in the South and Midwest. New Jersey had the highest median income, $61,672, while Mississippi had the lowest, $32,938.

President Bush, a Republican, has tried to make health care cheaper to buy by offering tax-free health-savings accounts and supporting efforts in Congress to allow small business more clout with insurance companies, a spokeswoman for the Office of Management and Budget, Christin Baker, said.

The Republican approach is leaving more children without insurance, Rep. Pete Stark, a Democrat of California, said in a statement.The Census Bureau found the number of children without health insurance rose to 8.3 million, or 11.2%, from 7.9 million, or 10.8%.

“The decrease in coverage is not an accident,” Mr. Stark said. “Republicans’ ‘consumer-driven health agenda’ is designed to dismantle the employerbased system and put more children and families on their own.”

The number of people getting insurance from employers and government programs was little changed, the Census Bureau said. About 174.8 million, or 59.8%, got their insurance through employers. About 80 million, or 27%, are covered by government programs, including 38.1 million, or 13%, on the state-federal Medicaid program for the poor.

About 37-million people live in poverty in this country, or about one in eight, the Census Bureau said. The rate and number were statistically unchanged from 2004, marking the end of four straight years of increases in the poverty rate.

“Every year as you move away from a recession, you expect the growth of the poverty rate to slow and eventually reverse,” an expert on child poverty at the Urban Institute in Washington, Austin Nichols, said.

The census considered a family of four poor if it had annual income of $19,971 or less. People living alone are considered poor if they make $9,973 or less. New Hampshire had the lowest percentage of poor residents, 7.5%. Mississippi had the highest, 21.3%.

Texas had the highest percentage of people lacking health insurance, 24.6%. Minnesota had the lowest percentage. 8.7%. The percentage of people living in America without health insurance rose to 15.9% last year from 15.6% in 2004, the government said. The number with health insurance rose by 1.4 million to 247.3 million.

Health costs are becoming more of a challenge for state officials, Mr. Blendon of Harvard said. Massachusetts passed the nation’s first law requiring all adults to have health insurance by July 1, 2007. Massachusetts will help some of its poorest residents buy insurance.

The cost of insurance bought through an employer increased 9.2% in 2005 as wages climbed 3.2%, according to the Henry J. Kaiser Family Foundation in Menlo Park, Calif.

Vermont, Illinois, Michigan, and Rhode Island also are working on plans to help residents of their states get insurance.

A lack of health insurance led Susan Squire, 57, of Warren, Mich., to file for bankruptcy in October. She had $91,000 in medical bills from a January 2005 heart attack and subsequent surgery. Ms. Squire, who was making about $21,000 a year with part-time bookkeeping work, said she tried to negotiate discounts.

“I paid some off. I paid some down. I was trying to pay them off one by one,” Ms. Squire said in a telephone interview. “Some went along with me, but the bulk of them did not. They started with the daily calls, the daily notices, the daily threats.”