In a novel attempt to extend health coverage to uninsured workers, 60 large employers are joining together to sponsor an array of low-cost health insurance options. The program, to begin in the fall, will be offered for at least two years and is intended to cover uninsured part-time and temporary workers, contractors, consultants and early retirees, who typically are not eligible for employer health plans.

The sponsors, which include General Electric, I.B.M., McDonald's and Sears, Roebuck, will begin promoting the low-cost plans in April and May to 3 million eligible workers, about 7 percent of the 45 million uninsured Americans. They hope that several hundred thousand people will sign up at the start.

The employers will not subsidize the coverage, but their participation created a pool of potential participants sufficiently large to justify lower insurance rates than individuals would have to pay on their own.

These options, to be offered to part-time employees, are not intended to replace employer-paid health plans that are already in place for full-time workers. The sponsors also acknowledged that these low-cost plans will not by themselves solve the problem of the uninsured.

The plans will range widely in cost from $5 a month for a card that provides users with discounts for doctors and pharmacies to more than $300 a month for a high-deductible plan that covers major medical and hospital expenses.

UnitedHealth Group will offer the four lowest-cost options in all 50 states. UnitedHealth and Humana will offer the major medical policies in states where they have been approved by regulators. Cigna will offer the program's major medical option in Arizona.

"Nothing like this has ever been done before," said Andy Slavitt, a UnitedHealth executive.

The 60 employers are supporting this program because they say they ultimately pay for the uninsured as hospitals pass on their costs for nonpaying patients. They expect the program to help reduce employee turnover and increase productivity among part-timers.

The low-cost options, they said, could also help older employees maintain some form of health coverage if they choose to stop working full time but cannot afford $25,000 or more a year to buy their own coverage.

Leaders in the group expressed hope that government policy makers might consider this approach in making health coverage more affordable. It may also be a way for employers to stave off proposed state mandates for coverage of uninsured workers.

In a referendum last fall, California voters overturned a 2003 law requiring companies to buy health insurance for workers and their families.

"We have a model that doesn't require enabling legislation," said Tom Beauregard, a health strategy specialist at Hewitt Associates, a benefits consulting firm. "The private sector can't wait for the government to act."

Beginning in September, all participants in the program will receive a card providing discounts from doctors, pharmacies and hospitals.

As an example, the card alone, without other benefits, will cost a 19-year-old woman working part time in Orlando, Fla., about $5 a month. The discounted price of a month's supply of the widely used cholesterol-lowering drug Lipitor, for example, would be $106.25, or $7.65 off the average retail price, UnitedHealth Group said.

For three different levels of monthly premiums, from $50 to $110, the Florida woman and her dependents would be covered for a varying number of medical services, including $450 a year for visits to doctors and deeper discounts on 10 drug prescriptions a year. For higher premiums, $264 and $303 a month, she could get a high-deductible major medical policy with a health savings account.

In recent surveys, uninsured workers said they would appreciate having a low-cost discount card. "Mothers wanted a card so they could take a child to a pediatrician instead of an emergency room," said Greg A. Lee, senior vice president of Sears, which has 100,000 part-time employees.

Mr. Lee, who led a committee that developed the low-cost package under the auspices of the HR Policy Association, a group of senior officials of large companies, said the association hoped that more companies would join the original 60 corporate sponsors. "If we can make the pool even larger, there is a good chance we will be able to continue to lower the price," he said.

The association plans to introduce the program at a conference of employers and consultants in Washington on Monday. For many uninsured workers, the premiums for even the high-deductible plans that some employers offer are unaffordable. "The average person who makes $30,000 a year spends $1,500 more than they make and has less than $500 in assets," Mr. Slavitt of UnitedHealth said. "Offering them insurance with a deductible is equivalent to not providing insurance at all."

Older employees thinking of retiring before they become eligible for Medicare are often "stunned to find that their health care premiums could easily be $20,000," said Jack Mollen, a senior vice president of EMC, an information management and storage technology company based in Hopkinton, Mass. "With the baby boomers getting older, companies will want to have programs that encourage more senior employees to go to part-time work or consulting," he added.

The appeal for early retirees is "the No. 1 sweet spot" in the program, said Dr. Robert S. Galvin, director of global health care for G.E. Although most G.E. employees have comprehensive health coverage, he notes that the company has acquired a number of small companies that can participate in the low-cost program. "We will be offering it," he said.

Dr. Galvin said the sponsors of the new program had asked the insurers to join G.E. and other large employers that were trying to persuade doctors and hospitals to meet quality and efficiency standards.

Workers in the low-cost program will also be able to compare health care providers on the program's Web site, he said.

"Being uninsured doesn't mean you want to be uninformed," Dr. Galvin said.

Mr. Beauregard of Hewitt Associates said the number of uninsured people would rise significantly in the next five years as employment continues the shift from manufacturing with strong unions to nonunion service jobs, often in small companies that do not offer health benefits. Even large businesses, he noted, are dropping retiree medical coverage.

"It is extraordinarily important," he said, "to address the issue of the uninsured for social, economic and even moral reasons."