What’s the scope of the work? Will the website be basic with just a few pages about your company, its services, and contact information? Or will it also have an e-commerce section for online shopping, a blog, or content for visitors to download? Before you hire a web designer, make sure you have a thorough, specific list of the components you must have the designer include in the web design.
This past September marked the first time a judge ruled that the ADA applies even to businesses without a physical location. Scribd, an e-book subscription service is considered to provide "a place of public accommodation." Their services are not accessible to blind persons because they cannot be read with a screen reader. The judge reasoned, "Now that the Internet plays such a critical role in the personal and professional lives of Americans, excluding disabled persons from access to covered entities that use it as their principal means of reaching the public would defeat the purpose of this important civil rights legislation."
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.
Additionally, in February 2018, Congress passed the ADA Education and Reform Act, a bill designed to make it harder for disabled Americans to sue businesses for discrimination. Republican lawmakers who wrote and passed the bill argue that the law will help curb “frivolous” lawsuits, while opponents have argued that this law will gut the ADA, essentially giving businesses little reason to follow the ADA guidelines at all.
Two agencies within the U.S. Department of Labor enforce parts of the ADA. The Office of Federal Contract Compliance Programs (OFCCP) has coordinating authority under the employment-related provisions of the ADA. The Civil Rights Center (CRC) is responsible for enforcing Title II of the ADA as it applies to the labor- and workforce-related practices of state and local governments and other public entities. Visit the Laws & Regulations subtopic for specific information on these provisions.

ADA disabilities include both mental and physical medical conditions. A condition does not need to be severe or permanent to be a disability.[6] Equal Employment Opportunity Commission regulations provide a list of conditions that should easily be concluded to be disabilities: deafness, blindness, an intellectual disability (formerly termed mental retardation), partially or completely missing limbs or mobility impairments requiring the use of a wheelchair, autism, cancer, cerebral palsy, diabetes, epilepsy, Human Immunodeficiency Virus (HIV) infection, multiple sclerosis, muscular dystrophy, major depressive disorder, bipolar disorder, post-traumatic stress disorder, obsessive compulsive disorder, and schizophrenia.[7] Other mental or physical health conditions also may be disabilities, depending on what the individual's symptoms would be in the absence of "mitigating measures" (medication, therapy, assistive devices, or other means of restoring function), during an "active episode" of the condition (if the condition is episodic).[7]
Another federal agency, the Architectural and Transportation Barriers Compliance Board (ATBCB), also known as the Access Board, issues guidelines to ensure that buildings, facilities and transit vehicles are accessible to people with disabilities. The Guidelines & Standards issued under the ADA and other laws establish design requirements for the construction and alteration of facilities. These standards apply to places of public accommodation, commercial facilities, and state and local government facilities.
The ADA has four main components: (1) requirements for maintaining medical records and requiring medical testing, (2) an employer must reasonably accommodate disabilities, (3) an employer may not discriminate against an individual with a disability, and (4) an employer may not retaliate against someone who opposes discrimination of participates in protected activity.
As a client, you might think web design comprises things like a homepage and a few interior page layouts, but web design is so much more. What about call-to-actions, buttons, and images? What about design flow? What about your navigation, headers, footers, and any side elements for up-selling products? Basically, design includes all the elements of your site, and they all need to flow with your color scheme and business idea.
This title requires telephone and Internet companies to provide a nationwide system of interstate and intrastate telecommunications relay services that allows individuals with hearing and speech disabilities to communicate over the telephone. This title also requires closed captioning of federally funded public service announcements.  This title is regulated by the Federal Communication Commission. 
Thanks for writing. While I’m not a lawyer I believe if your physical practice is ADA exempt your web presence, as an extension of that physical business would maintain the same exemption status. If you’d like to be absolutely certain I’d confer with an ADA lawyer (email us, questions at yokoco dot com if you need a referral) but I don’t believe you have reason to worry.
This is the exact opposite of mistake #1. Let me start by revealing a dirty little secret when it comes to website design. Most people think, Oh, I’m going to hire a professional website firm because I want a “real website” As opposed to a Word Press website or something else. And what most people don't realize is that all websites are made from the same stuff.

Navigable: Content that’s repeated on multiple pages can be easily skipped. All pages have informative titles, headings, and labels that describe the page’s content and hierarchy. Navigating the page must take place sequentially, in a meaningful order that preserves relationships on the page. All link text is descriptive in order to make clear where the link will take users. If users are navigating via a keyboard, the current focus of the keyboard is always highlighted and visible.
Title II of the ADA prohibits discrimination against qualified individuals with disabilities in all programs, activities, and services of public entities. It applies to all state and local governments, their departments and agencies, and any other instrumentalities or special purpose districts of state or local governments. It clarifies the requirements of section 504 of the Rehabilitation Act of 1973, as amended, for public transportation systems that receive federal financial assistance, and extends coverage to all public entities that provide public transportation, whether or not they receive federal financial assistance. It establishes detailed standards for the operation of public transit systems, including commuter and intercity rail (e.g., AMTRAK).