Sixty percent of women and 27 percent of men in the military reserves and the National Guard suffer sexual assault or harassment during their service, according to a long-overdue report released yesterday by a congressional committee.

The Department of Veterans Affairs report said its surveys showed that 11 percent of women serving in the reserves or National Guard experienced rape or attempted rape, compared with 1.2 percent of males. More than half of the incidents took place at a military work site and during duty hours, and in most cases military personnel were the offenders, it found.

Congress authorized the report in 1999 -- for completion in 2001 -- to investigate whether reserve forces experience sexual trauma at rates similar to those suffered by active-duty forces. The report concludes that they do, and suggests that the cost of treatment for victims is significantly higher than currently budgeted.

The rates "are consistent with active-duty populations, they are very similar, but they are higher than civilian prevalence rates," said Jane Stafford, who coordinated the project as a VA employee but has since left the department.

Democratic lawmakers said they are especially concerned that the tens of thousands of military reservists -- including an increasing percentage of women -- serving lengthy tours in Iraq and Afghanistan will not receive adequate care for any sexual assault when they return. Concern over sexual assault in the military has heightened in recent years amid reports of incidents among deployed forces, leading the Pentagon to adopt policies providing for "victim advocates" to assist service members in gaining help.

Rep. Lane Evans (Ill.), the ranking Democrat on the House Veterans' Affairs Committee, yesterday in a statement criticized the Bush administration for "attempting to hide" the study.

"The women and men who have suffered military sexual trauma deserve our respect, compassion and commitment to provide them with ready access to counseling and treatment. I am releasing the report, which I have obtained through other sources, to shine a light on a serious problem that the White House wants to hide in the shadows," Evans said. The report, although due in 2001, was not completed until 2003.

VA officials said the report was not released because it still in the final stages of review. Department spokesman Scott Hogenson, explaining the nearly two-year delay in releasing the study, told the Associated Press that officials were checking the facts.

Defense Department spokesman Roger Kaplan told the AP that the survey "tells us that we were correct in placing greater emphasis on combating sexual assault and sexual harassment in the active and reserve components." He said more recent surveys show lower rates of harassment and sexual assaults in the military.

The report estimated that the annual cost for health care and mental treatment for National Guard members who experience sexual trauma -- defined as rape, sexual assault or sexual harassment -- would be $20 million, compared with the $13 million budgeted for that care for fiscal 2006 by the Veterans Affairs Department. But the cost could reach as high as $900 million over 10 years, it said.

Fewer than 19 percent of those reservists surveyed reported that they received any help for the trauma, and fewer than 2 percent sought care from Veterans Affairs, according to the report. The report was based on phone interviews in 2002 and 2003 with about 4,000 former reservists who had served between 1950 and 2000.

In recognition of the problem, the department a year ago began to allow reservists to receive treatment for sexual trauma for two years after departure from service.