Expecting the unexpected. No one likes contemplating "what ifs," but being prepared for when the clouds roll in is important. Far too many people have found themselves suddenly unable to earn an income due to an illness or injury they did not anticipate.

Having at least six months living expenses saved up—plus a sufficient amount of disability coverage—can protect yourself and your loved ones if you find yourself without a source of income, experts say.

But these days, disability insurance is almost as hard to come by as flood insurance. According to the Council for Disability Awareness (CDA), an insurance-industry supported trade group, only 1 out of every 3 employers offers disability benefits even though Social Security Administration statistics claim 1 in 8 workers will be disabled during their careers.

And, much like health insurance, employers are shifting more costs onto their employees and the trimming, or elimination of benefits is emerging in the world of disability benefits.

Industry professionals suggest that workers examine their disability insurance coverage to be sure its adequate—and buy additional coverage, if necessary. "Many people assume they'll never become disabled so they don't give disability insurance benefits the same scrutiny as their health insurance benefits," says Bill McLaughlin, an insurance broker with Widerman & Company, a New Jersey-based financial services business.

Though many guess accidents generate the majority of disability insurance claims, the CDA says illnesses make up 90 percent of the payouts. Topping the list—musculoskeletal conditions such as arthritis and back problems. Cancer is number two. Need more convincing? Medical problems contributed to 62 percent of personal bankruptcies filed in the US in 2007 and half of all home foreclosures in 2006.

Something else to keep in mind: any employed person is eligible to apply for Social Security Disability Insurance but the average benefit is less than $1,200 per month with a typical claim lasting about 2.5 years. (Your eligibility and benefits are based on the number of years you've been contributing to Social Security. For more information, visit the Social Security website: www.ssa.gov).

How to Buy Enough Disability Insurance

Gather information. Speak to your company's human resources department to discuss the details about coverage through your employer. Many employers offer basic coverage and allow employees to buy more coverage through the company. In 2010, a typically employee-paid disability plan cost $350 per year. Individual plans are more expensive—$3,000 per year and up-but usually more comprehensive as well. A combination of employer plus supplemental insurance will generally replace 70 percent of a person's income.

Find out the terms. If you do have coverage at work, read the fine print to be sure you have both short and long-term coverage. Short-term coverage tends to last a few months); long-term pays after a set time period—usually 90 to 180 days.

Mind the gap. Be sure the short-term policy stretches far enough for coverage before long-term benefits start.

Calculate your Personal Disability Quotient (PDQ). You can learn your chances of becoming disabled by visiting www.whatsmypdq.org, a website created by the CDA.

Know the numbers. Long-term disability insurance generally pays a percentage of your pre-disability income. While 60 percent is typical, it may not include extra income such as a bonus.

Get advice from a professional. Meet with a reputable insurance broker to run your disability numbers and consider buying additional coverage. McLaughlin admits getting disability coverage through your job (with the premium coming directly out of your paycheck) is likely the most cost-effective way to have it. "Disability insurance is expensive but if your employer doesn't offer that benefit—and you have any sort of liability like kids and mortgage—it's irresponsible to live without it," McLaughlin says. "Everyone who works needs disability insurance to protect their most important asset-their ability to earn an income."

If You Do Decide You Need Addition Coverage, Be Aware of the Following Conditions

Know what triggers the payout. Understanding the policy's definition of what constitutes a disability can be eye opening. Be sure the policy doesn't contain a disclaimer barring you from money if you can do a comparable job. It's preferable if you get money when the policy states you can't do your current job.

Factor in Social Security. Most private disability policies require you to apply for Social Security benefits first and then subtract the government's payout from what the insurer pays, so beware. This is referred to as an "offset." Plus, although disabled people who receive Social Security benefits can quality for Medicare, there is often a lag time of up to two years before federal health coverage kicks in.

Bill McLaughlin reviewed this article.