Because web designers tend to work as freelancers on a project basis, they must be excellent communicators, willing to manage their own work, and available on your schedule. Some critical skills, such as working collaboratively and responding enthusiastically to feedback, aren’t core to good web design, but make working with a web designer much easier. Finally, look for a web designer who has cross-functional knowledge, such as understanding marketing and conversion rate optimization in addition to web design.
While legal considerations might be your biggest worry, making your site more accessible is simply good customer service. More than 39 million Americans are blind and another 246 million have "low vision," Another one million are deaf in the U.S. Add to that people with mobility issues that prevent them from using their hands and that's a huge portion of the country's buying power.
The Americans with Disabilities Act of 1990 or ADA (42 U.S.C. § 12101) is a civil rights law that prohibits discrimination based on disability. It affords similar protections against discrimination to Americans with disabilities as the Civil Rights Act of 1964, which made discrimination based on race, religion, sex, national origin, and other characteristics illegal. In addition, unlike the Civil Rights Act, the ADA also requires covered employers to provide reasonable accommodations to employees with disabilities, and imposes accessibility requirements on public accommodations.