The heart attack and two heart operations were frightening enough for Maria Gloria Zelaya. Then the five-figure bill from Inova Fairfax Hospital came, and she was terrified.

Zelaya, 52, an unemployed and uninsured Alexandria resident, spent five days in the hospital in December. She said she received good treatment, but she never expected it would cost her about $56,000.

"They did not explain it to me," Zelaya, who immigrated to the United States from El Salvador 27 years ago, said in Spanish. "I was very scared."

Zelaya is resting a bit easier now. For one thing, she is working out a payment plan with the hospital. But even more of a relief is the knowledge that under a new Inova Health System policy, future hospital visits are unlikely to be so pricey.

Inova Health System, which runs five hospitals in Northern Virginia, has begun offering a 35 percent discount to patients without insurance. The policy is being praised by patient advocacy groups and consumers such as Zelaya, who say that for too long hospitals have hit those least able to pay -- people who earn too much to qualify for full coverage under programs for the poor but too little to afford private health insurance -- with the highest charges.

In recent years, the hospital industry has come under fire for charging uninsured patients more than they charge those covered by private or government-sponsored plans, which negotiate lower rates. Hospital officials had argued that price breaks to the uninsured would violate complicated federal Medicare rules.

But U.S. Health and Human Services Secretary Tommy G. Thompson struck down that argument in February and encouraged hospitals to give discounts to the 44 million Americans without health insurance.

Inova introduced its policy in January, and other hospitals in the region say they plan to offer similar discounts. According to Families USA, a consumer organization based in the District, at least 785,000 Virginia residents are uninsured -- including 27.6 percent of Hispanics, the group most likely to lack health coverage.

"Hospitals in general are looking at and updating their billing practices in light of the fact that they're seeing more non-poor patients who don't qualify for their charity programs," said Elizabeth S. Long, vice president of the Virginia Hospital and Health Care Association.

Zelaya, whose husband earns $19,000 a year as a mechanic, did not qualify for Medicaid, the federal health insurance program for the poor. Inova's "charity care" program covered only part of her treatment.

Under the new policy -- instituted after Zelaya's treatment -- Inova discounts all uninsured patients' fees, even if those fees have already been reduced by the charity program, said Beth Visioli, a hospital spokeswoman. About 11 percent of the hospital system's patients are uninsured.

"It was the right thing to do," Visioli said, explaining Inova's reason for implementing the policy. "We're always considering the possibilities of the ways we can assist the community. . . . Our mission is to provide health care to people who otherwise can't afford it."

Inova's discount program represents a huge victory for uninsured patients, but only if patients know about it, said Edgar Rivera of the Alexandria-based Tenants' and Workers' Support Committee, which has criticized Inova's billing practices. Last week, the group held a news conference outside Inova Mount Vernon Hospital to draw attention to the program.

"If your policy is in the drawer and nobody knows about it, you might as well not have it," Rivera said.

Often, the uninsured -- especially immigrants who speak limited English -- have a hard time navigating complex payment systems, and hospitals do not always explain the options available to them, said Sonya Schwartz, a health policy analyst for Families USA. And even with the discount, care might be too costly for patients without insurance, she said.

Inova officials say the health insurance crisis must be solved at the national level and insist they work hard to guide patients through the billing process. The Inova system does not advertise the discount specifically, but financial counselors explain payment choices to all uninsured patients, and translators are available, Visioli said. Signs -- written in five languages -- telling patients that counselors are on hand are posted in all hospital registration areas, she said.

"We really focus one on one with patients and view everything on a case-by-case basis," she said.

The discount is good news to Abdullahi Mohamud, 44, an uninsured taxi driver and father of three from Alexandria.

In the past, the threat of huge hospital bills has forced Mohamud and his family to "ignore the pain . . . and just buy over-the-counter [remedies]," he said. "We will appreciate the help. . . . We need it."