For years, Carl Brown had a health insurance plan that covered his every medical need.

The Bloomington, Ind., man, working as a printer for Indiana University, paid just $1 a month for a broad array of coverage with low co-payments.

That ended when he was laid off in 2001. Since then, Brown, 52, has been able to find other printing jobs, but none offering healthcare coverage.

Even as Indiana and other states consider ways to help insure the working poor, Brown's case illustrates a surprising trend: The struggle to obtain affordable health insurance is rapidly reaching into middle-class America.

More than one-third of the 46 million uninsured in the United States live in households with incomes of more than $40,000. The nation's median household income was $46,326 in 2005. These people are among the fastest-growing subgroup of uninsured today.

For both the poor and the middle class, being uninsured carries many of the same consequences: increased health problems, lower work productivity and billions of dollars in uncovered care that must be written off by doctors and hospitals or passed on to patients with insurance.

In the case of Brown, whose earnings are above Indiana's median income of about $41,000, living without insurance is a deliberate gamble. He could buy an individual policy, though its price would strain his finances. Many are in the same boat. But for many others, the cost of coverage or pre-existing medical problems make insurance too expensive or impossible to obtain.

The problem has become so profound that presidential candidates are once again talking about the idea of a government-run universal health plan.

Brown knows he's taking big risks in leaving himself uncovered.

"I've played the odds," he said. "I've been lucky. But eventually, the odds are going to catch up with me. That worry is always there, in the back of my mind."

Myra Stewart, 59, of Martinsville, Ind., is also taking a risk by going without insurance. For 25 years, Stewart — diagnosed with multiple sclerosis 20 years ago but still symptom-free — had group coverage through her jobs at speaker factories.

But in 2004, she left her job to start her own business. After being denied coverage by many companies because of her disease, she waded through a variety of confusing options before settling on an individual policy that cost about $110 a month. It sounded like a terrific deal, but the company never reimbursed her for a single claim. So after about six months, she dropped the coverage.

"My health is pretty good," Stewart said. "My main concern is if I have a car wreck or something catastrophic happens and I need surgery or end up in the hospital for a while."

Employment-based group insurance remains the largest source of health coverage in the United States, accounting for 62 percent of those insured. Individual-purchased coverage has remained steady nationally at about 7 percent since 1994.

But costs for both plans are rising rapidly, prompting employers to shift more of the cost to workers or stop offering coverage altogether.

For many trying to enter the individual coverage market, the cost can cause sticker shock, said Jessica Waltman, a vice president of the National Association of Health Underwriters.

"Many of these people are coming from a situation where they had group coverage and the employer picked up all or at least the lion's share of the cost," she said. "Often, they have no idea of what insurance really costs."

Rates for individual policies can run anywhere from a few hundred dollars to more than $2,000 a month — depending on a person's age and health history — and consumers are facing ever-increasing deductibles and out-of-pocket spending.

Jude Thompson, president of individual markets for WellPoint, the nation's largest health insurer, said the traditional one-size-fits-all approach to marketing insurance no longer works.

"That's one of the big reasons why we're where we are today with the uninsured," he said. "Companies need to change the way they are talking about insurance and offer different products with different price points. We need products that resonate with the different age and income groups and hit the mark with people who can and want to purchase insurance."