Nearly a quarter of 20-year-olds and one-third of those between 35 and 65 will find themselves disabled before they retire, the government says.
Half of those disabled for more than three months remain disabled for more than two years, according to the Society of Actuaries - a significant financial burden for all but the wealthiest Americans.
But most won't find out until their vacation days run out that their lost income isn't covered by any insurance plan, said Tom Watjen, president and CEO of Chattanooga-based Unum.
"As we all know too well, since many Americans live paycheck to paycheck, most Americans are unable to live with lost income," Watjen said.
In fact, a new survey shows that fewer than half of employees making less than $25,000 are offered disability insurance at work, and only 13 percent of workers say they know "a lot" about this type of insurance.
The scientific survey, commissioned by Chattanooga-based Unum and the Consumer Federation of America, polled about 1,200 workers to find out what their plan was if they found out they were disabled.
The problem is, few Americans have a plan.
Disability insurance typically costs between $10 and $30 per month, and the survey showed that more than 90 percent of workers said they would gladly pay the premiums - if they knew about them.
Workers who work for small or medium-size employers are the least likely to know about this type of coverage, especially those with incomes under $50,000, the survey found. About two-thirds of employees under 34 and all workers making less than $50,000 admitted to knowing "not very much" or "nothing at all" about disability insurance, according to the survey.
Most respondants making more that $100,000 know about disability insurance but are less likely to need coverage, the survey found, since wealthier workers tend to have more assets on hand to survive periods without pay.
One possible solution - a tax break to incentivize small businesses to offer the coverage - is still in its infancy, said Steve Brobeck, executive director of the Consumer Federation of America.
"There's quaite a lot of skepticism in Congress about creating new tax incentives," Brobeck said.
But workers themselves don't appear to share in that skepticism.
"The vast majority of respondants believe the federal government should offer incentives to employers to offer this type of coverage to employees," said Watjen.
At the very least, "there's certainly more that the government can do to raise awareness of the need for this coverage," Watjen said.
In the meantime, many workers are confused about whether disability insurance is even offered at their job, he said, which is "especially true of employees who are young,"
They weren't so confused about whether they wanted the insurance, however.
"Consumers, once they understand the need for this type insurance, overwhelmingly wanted it even If they had to pay for it themselves," Watjen said.