A 40-year-old talent scout in New York, Thomas Scott, said he accepted a job recently with the understanding that his employer would pay him a $150-a-month stipend to cover health insurance. Then, Mr. Scott said, the Los Angeles-based agency, which he declined to name for fear of losing his job, reneged on the promise. Because, he says, he doesn’t earn enough salary to pay for it himself, Mr. Scott is now uninsured.

He is one of a growing number of New Yorkers who are gainfully employed but lack health insurance. In a study published last month, the United Hospital Fund reported that more than 80% of the state’s uninsured are workers or their dependents.

There are 2.4 million uninsured New Yorkers, including 1.2 million living in New York City. Between 2004 and 2006, the number of uninsured jumped 1.8% statewide and 1.2% in the city. During the same period, employer-sponsored coverage plummeted 1.6% in New York State and 2% in New York City.

Analysts said the increase came after years in which the number of uninsured New Yorkers was dropping, mostly because of the expansion of public health insurance programs. “The success of the public programs was a real reason we saw a decline in the uninsured,” a co-director of the fund’s Health Insurance Project, Danielle Holahan, said.

Employers are dropping health insurance for their employees because of the rising cost of coverage, some business experts said. About 9.7 million New Yorkers — or 59% — have employer-sponsored coverage, accounting for about $43 billion in premium payments.

According to the executive director of the New York Business Group on Health, Laurel Pickering, the ability to provide insurance depends on the size of the company. “Smaller businesses are more likely to not be able to afford insurance coverage,” she said. Larger companies tend to offer health benefits as a way of attracting and retaining employees.

Some people who are self-employed also find they cannot afford insurance. Last year, a 53-year-old computer consultant, Robert Eisenhardt, lost his insurance when he left his job to start his own company. “It’s been about six months, so I’ve been living a kind of terrified life,” Mr. Eisenhardt said, describing his time being uninsured. As he works to get his business off the ground, he said his most immediate concern is having a positive cash flow. “Last year I had a prostate cancer check. I’ve got to have it again. Do I want to pay for it again? No, I don’t,” Mr. Eisenhardt, who is considering purchasing health insurance through the Freelancers Union, said.

There is also a category of employees who lack insurance because they earn too little to purchase insurance but too much to qualify for public coverage.

“I have patients who have been diagnosed with cancer and have no insurance, and they don’t qualify for Medicaid. There’s not really much I can do,” the assistant director of operations at the William F. Ryan Community Health Center on the Upper West Side, Miriam Ruiz, said. “They have to wait until they have a severe emergency to go to the emergency room.”

Health experts estimate that nearly 40% of uninsured New Yorkers are eligible for public health insurance. The city’s public hospital system, the Health and Hospitals Corp., targets those patients and seeks to enroll them in insurance programs. About 100,000 patients have signed up for one of its programs, HHC Options, according to a senior associate director in HHC’s Elmhurst Hospital Center, Evelyn Luciano. “Those would be people who do not qualify for public insurance and don’t have insurance” of their own, she said.

One Brooklyn woman, Yuliya Dudnik, recently found herself in this kind of limbo because she and her husband earned $10,000 more last year than they did the year before. He works as a cabinet maker and she is a part-time paramedic.

Mrs. Dudnik said they are not eligible to renew their Medicaid coverage, but with a combined income of $35,000, the couple cannot afford any other insurance. Both suffer from chronic health problems — he has a bad back, and she has stomach ulcers — and without insurance, Mrs. Dudnik said they will be forced to forgo medical care.

“I don’t ask for free insurance,” she said. “I just want insurance for reasonable money.”