Leading web developers have been pioneering accessibility and publishing standards since 1994. In 1999, the Web Accessibility Initiative (WAI) and the World Wide Web Consortium (W3C) created the Web Content Accessibility Guidelines (WCAG). In essence, the people who determine how the internet is written came together to advise web developers on how to make websites accessible not only to people with disabilities, but to all web users, including those with highly limited devices.
This is the reason why I think web design firms have to position themselves as solution providers and not just web guys/gals. A client doesn't need a website, they need sales. The website is just part of that solution but it's not the solution and unlike web design, service like email marketing automation, SEO, and PPC requires an experienced professional.
Government Code §11546.7 – The requirement that state agency heads certify, every two years, that their agency’s website meets the Web Content Accessibility Guidelines, Version 2.0 or a subsequent version, at Level AA or higher, and the requirements of Sections 11135 and 7405 of the Government Code. Created by AB 434 (Baker, Chapter 780, Statutes of 2017), and sometimes referred to as AB 434.
The ADA is the Americans with Disabilities Act, passed almost 30 years ago in 1990. This act was originally put in motion pertaining solely to physical location. It requires establishments to provide people with disabilities easy access to various levels throughout the business. This act was set to achieve an equal experience to all people, handicapped or not.