An advisory task force has called for more free care at District health clinics as part of a multiple attack on the problems of the estimated one in six District residents lacking health insurance.

The Advisory Task Force on Residents Without Health Insurance, jointly sponsored by the District's Department of Human Services and the Health Equal Access League of the District of Columbia, issued its 85-page report last week after eight months of study. Among its 10 major recommendations, the group urged: That uninsured residents with incomes less than twice the federal poverty level -- which is about $5,600 for individuals and $11,200 for a family of four -- receive free care at District public health clinics. About 225,000 District residents are in families with incomes below twice the poverty level, but many are covered by Medicaid or some other form of insurance.That the District "develop a financing mechanism" for providing health coverage for the more than 100,000 medically uninsured residents. That all District hospitals and clinics extend their weekend and evening hours and step up outreach campaigns to educate consumers -- particularly undocumented immigrants, non-English-speaking residents and minorities -- on how to obtain health care and avoid unnecessary use of hospital emergency rooms.

Between 100,000 and 140,000 District residents have no health insurance at all, the report estimates. Thousands more are underinsured because they have insurance policies with large gaps in coverage.

The uninsured include the homeless, the near-poor whose incomes are just large enough to exclude them from Medicaid benefits, and undocumented immigrants. About half are either self-employed or working part-time or in low-paying jobs with companies that do not offer health insurance benefits.

In the District, most single persons become ineligible for basic Medicaid coverage if their annual income exceeds $4,344. The cutoff is higher for residents with larger families, for expectant mothers and for those who are blind, disabled or aged.

A 1983 survey by the Washington Urban League found that 51 percent of District households headed by Hispanics lacked family health coverage, compared with 26 percent of households headed by blacks and 10 percent of those headed by whites.

The 35-member advisory task force included doctors, nurses, health officials and representatives of business, labor and the insurance industry and other community leaders. It was headed by Dr. Jesse Barber, professor of social medicine and neurosurgery at Howard University College of Medicine.

The task force's recommendations have been sent to M. Jerome Woods, director of the District's Department of Human Services, and a formal response from the department is due within 60 days, said task force vice-chair Marsha Lillie-Blanton.

The task force report offers "a very important road map," said Dr. Reed Tuckson, public health commissioner of the District, emphasizing that health officials already have begun implementing some of the recommendations.

For example, District health clinics in Wards 7 and 8 are now open Wednesday evenings until 9, Tuckson said, and other clinics also are considering staying open one evening a week.

But Tuckson acknowledged that some of the task force's other recommendations will require more time and effort.

The District has extended Medicaid coverage as far as the national law will allow, he said. Under Medicaid, a federal-state health program for the poor, states have considerable leeway in deciding which kinds of care will be covered and for whom.

"We have extended Medicaid coverage to the full range of the law for the elderly, the disabled and prenatal care," Tuckson said. "We are as liberal as you can possibly be within the limits of the Medicaid law."

A controversial issue still being debated is whether patients at public health clinics should be charged on a sliding fee scale, depending on their income. The District, which now provides prenatal care free for women with incomes of less than $20,000, is studying whether graduated fees are a deterrent to patients needing other types of care, or whether they are an appropriate source of revenue.

"That analysis is beginning," Tuckson said. "It's not well along the way."

Tuckson said he had also created a "bureaucracy buster" position within his office, a person whose job is to build a network of primary care referrals and help patients find a doctor.

The "number one thing on my agenda," Tuckson said, is creation of a network of primary health care for the poor. Health officials are working with the D.C. Hospital Association to improve care for poor residents, he said.

District hospitals provided more than $100 million in uncompensated care last year to indigent and uninsured residents.