The number of Americans without health insurance rose by 800,000 last year, reaching a record high of nearly 46 million, the U.S. Census Bureau reported Tuesday.

Officials blamed the increase in part on the continuing erosion of workplace-sponsored health insurance. A majority of Americans still get their coverage by sharing costs with their employer, though a smaller and smaller percentage of American jobs are now accompanied by medical benefits.

The number of Americans with no private or public medical coverage increased from 45 million in 2003 to 45.8 million in 2004, though the percentage of the population without insurance held steady at 15.7 percent.

Twenty-one million full-time workers had no health insurance in 2004, a 0.6 percent increase from the previous year, census officials said.

Workers' Health Care Costs Continue to Rise

Public Insurance vs. Private Insurance

Officials attributed that overall stability to public insurance programs for the poor, including Medicaid and the State Children's Health Insurance Program (SCHIP). Those programs saw a half-percent increase in coverage rates, nearly offsetting insurance losses in private insurance.

At the same time, 11.2 percent of American children remained uninsured in 2004, according to the figures.

Medical groups and advocacy organizations have urged elected officials to tackle the rising number of uninsured Americans, though the issue has proved to be one of the most politically contentious long-term issues in Washington.

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View From the White House

President Bush has proposed a system of government tax credits designed to help families purchase insurance, though the White House has made no moves to spur action in Congress. Critics say that the $1,000 credits will do little to help most families buy coverage, which now costs upwards of $10,000 per year for the average family of four, according to the Kaiser Family Foundation.

Bush also backs a plan allowing small businesses to join in purchasing worker coverage, though Congress has yet to approve the program.

Robert Helms, a health policy analyst at the American Enterprise Institute, argues that Tuesday's numbers give lawmakers little incentive to treat the nation's uninsured problem as a crisis.

"It doesn't put any increasing pressure on the politicians to do anything about this, and they don't seem to be inclined to do anything anyway," he tells WebMD.

The White House has proposed $10 billion in cuts to Medicaid to rein in 7 percent annual rises in program costs. But program advocates attacked the proposal Tuesday, noting that Medicaid provided a cushion that offset falling rates of employer-sponsored insurance in 2004.

"Americans are playing by the rules, they're working, they're waking up every morning to go to their jobs and they have no health security. Cuts to Medicaid are the wrong direction to move," says Kathleen Stoll, director of health policy for the consumer health group Families USA.

The group points out that 4.6 million more Americans lack medical coverage now than in 2001. "It's pretty much an epidemic of physical and financial crises for Americans here," she says.

Taxpayers to Pay Majority of Health Care Costs

By Todd Zwillich, reviewed by Brunilda Nazario, MD

SOURCES: U.S. Census Bureau: "Income, Poverty, and Health Insurance Coverage in the United States: 2004," Aug. 30, 2005. Robert Helms, resident scholar in health policy, American Enterprise Institute. Kathleen Stoll, health policy director, Families USA.