U.S. health carriers covered 247.3 million people in 2005, up from 245.9 million people in 2004, but the percentage of residents lacking coverage also increased.

The total number of uninsured residents increased to 46.6 million, from 45.3 million, and the percentage of all U.S. residents who were uninsured increased to 15.9%, from 15.6%, according to a new report from the Census Bureau.

Government health programs have helped cut the rate of uninsurance among children in recent years. In 2005, that progress stopped: The proportion of children lacking health coverage increased to 11.2%, from 10.8%.

The proportion of U.S. residents covered by employment-based health coverage fell slightly to 59.5%, from 59.8%.

But U.S. residents ages 25 to 34 suffered a steeper drop in insurance rates than any other age group. The proportion of residents in the 25-34 age group who were uninsured jumped 0.9% in 2005, to 26.4%.

Residents in households with annual incomes of $25,000 to $74,999 were also hard hit.

The proportion of residents in the $25,000-$49,999 income category who were uninsured increased 0.8%, to 20.6%, and the uninsured rate for residents in the $50,000-$74,999 category increased 1%, to 14.1%.

The census report provides a “stark reminder of how the challenge of providing access to affordable coverage should be the nation’s top domestic priority,” according to officials at America’s Health Insurance Plans, Washington.

“Meeting this challenge of providing access to affordable coverage requires a collaborative effort between public and private entities coupled with the regulatory flexibility that will allow health insurance plans to offer more affordable products to purchasers and consumers,” AHIP President Karen Ignagni says in a statement.