As the nation struggles to improve medical and mental health care for military personnel returning from Afghanistan and Iraq, about 1.8 million U.S. veterans under age 65 lack even basic health insurance or access to care at Veterans Affairs hospitals, a new study has found. The ranks of uninsured veterans have increased by 290,000 since 2000, said Stephanie J. Woolhandler, the Harvard Medical School professor who presented her findings yesterday before the House Committee on Veterans Affairs. About 12.7 percent of non-elderly veterans -- or one in eight -- lacked health coverage in 2004, the most recent year for which figures are available, she said, up from 9.9 percent in 2000. Veterans 65 and older are eligible for Medicare. About 45 million Americans, or 15 percent of the population, were uninsured in 2005, the Census Bureau reports. "The data is showing that many veterans have no coverage and they're sick and need care and can't get it," Woolhandler said. Woolhandler's findings are based on data from two national surveys -- the Current Population Survey administered by the Census Bureau and the National Health Interview Survey administered by the Department of Health and Human Services. Veterans who said they had neither health insurance nor veterans or military health care were counted as uninsured. Woolhandler is a well-known advocate of guaranteeing access to health care for all Americans through a government-run national health insurance program. Republican lawmakers seized on that association to question whether she was trying to advance that goal with her study. "The difficulty would be that because of your desire for universal health care, that could influence how you felt about veterans," Rep. Cliff Stearns (R-Fla.) said. Woolhandler said the data are sound. She has firsthand experience with the issue as well, she said, because as a physician she has seen uninsured veterans with untreated high blood pressure, diabetes and other conditions. "It breaks my heart," she said. "The VA should be an important safety net for my patients, and it's not." Nearly 8 million veterans were enrolled in the VA health system in 2006.  The focus of the hearing was whether to open VA hospitals' doors to so-called Priority 8 veterans, who have no service-connected disabilities and whose earnings generally are above 80 percent of the median income where they live. Doing so would add significantly to VA's caseload and costs -- estimates range from $366 million to $3.3 billion annually -- and some veterans groups and lawmakers are concerned that it would make it  harder for veterans with serious service-related health problems to get timely care. Only about half of the 1.8 million uninsured veterans are classified Priority 8, Woolhandler said. The rest may technically be eligible for some VA care but live too far from its facilities for it to be a real option, she said. Rep. Steve Buyer (Ind.), the committee's ranking Republican, said Veterans Affairs should focus on its "core constituency" -- veterans with service-related health problems, the indigent and those with "catastrophic" disabilities. "Some say the government is obliged to provide essentially free health care for life to anyone who served even a year or two," he said. "I intend to protect the core constituency first." But Rep. Bob Filner (D-Calif.), the committee's chairman, said taking care of veterans is a continuing cost of war. "All veterans should have access to 'their' health-care system," he said. "This is rationing health care to veterans, those who have served our nation. And I think it's unacceptable for a nation of our wealth and our ability."