Roughly 40 million Americans, or 12 percent of the adult population, have a disability, according to research by the U.S. Department of Health and Human Services that was recently analyzed by the Center for Disease Control and Prevention.

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The National Health Interview Survey data from 2011 to 2014 also highlights the extent to which those with disabilities endure much greater economic hardship than others.

Those with one disability are more than twice as likely to live in poverty, lack a high school diploma, or be unemployed than those without a handicap, according to the research. For those with multiple disabilities, the economic outlook is even worse.

Employed people with disabilities also make far less on average than others. Just over 60 percent of the disabled population has an income below 200 percent of the federal poverty level, a rate more than twice that of the general population.

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The barriers to prosperity for people with disabilities are great and have been widely documented. Transportation challenges make it more difficult with those with physical handicaps to get and hold jobs. While discrimination based on disability is illegal, there is undoubtedly plenty of it, both conscious and unconscious, on the part of employers.

Indeed, a 2012 study by the Bureau of Labor and Statistics found that more than half of those with a disability report facing some type of employment barrier, including “lack of education or training, lack of transportation, the need for special features at the job and a person's own disability.”

Nonprofits and government agencies are encouraging employers to understand the benefits of hiring people with disabilities.

Related: Feds seeks to increase job opportunities for disabled

The U.S. Department of Labor recently announced a seventh round of funding for the ongoing Disability Employment Initiative, which connects disabled people seeking jobs with potential employers. Most of the money is doled out to state governments, which use the money on job centers and training programs aimed at increasing employment among the disabled population.