If you do get sued, if you immediately remediate your website, you may be able to get the lawsuit dismissed on mootness (there’s no longer anything in dispute, i.e. plaintiffs are arguing your website is inaccessible but you’ve already made it accessible). This definitely does not mean you should wait to fix your website but it does mean you may have an out.

The Americans with Disabilities Act (ADA) and, if the government entities receive federal funding, the Rehabilitation Act of 1973 generally require that state and local governments provide qualified individuals with disabilities equal access to their programs, services, or activities unless doing so would fundamentally alter the nature of their programs, services, or activities or would impose an undue burden.2 One way to help meet these requirements is to ensure that government websites have accessible features for people with disabilities, using the simple steps described in this document. An agency with an inaccessible website may also meet its legal obligations by providing an alternative accessible way for citizens to use the programs or services, such as a staffed telephone information line. These alternatives, however, are unlikely to provide an equal degree of access in terms of hours of operation and the range of options and programs available.
HiSoftware Compliance Sherrif Web, offered through HiSoftware Inc., is a platform that monitors and helps to enforce web accessibility guidelines on public web sites and portals and intranets. This program enables organizations to easily validate and watch content on their sites, checking them for compliance contrary to standards-based (WCAG, Section 508) and custom policies for accessibility.
There are many different kinds of automated testing tools that can currently be used as ADA website compliance checkers. Some are free of charge, while others come with a cost. Some can be used online. Some must be downloaded and installed before use. The World Wide Web Consortium keeps an online database of checkers, called the Web Accessibility Evaluation Tools List, that can be filtered according to a web designer’s needs.9
The Department of Justice (DOJ) has specifically stated in rulings that websites should be designed so they are accessible to individuals who have vision, hearing, and physical disabilities. There’s a growing body of case law where the DOJ required companies to provide an ADA compliant website and levied hefty penalties when sites failed to measure up.
AMP generates reports of evaluation results and provides users step-by-step evaluation guidance. The report format is in HTML. AMP is an online checker, hosted service and server installation. The program automatically checks groups of web pages, websites or single web pages, as well as password protected or restricted pages. Browser plugins include Firefox, Internet Explorer 8, and Internet Explorer 9. Suggest formats are PDF documents, CSS, HTML, XHTML, PDF, XML Javascript, AJAX, and ARIA. The most recent version was released on June 1, 2004. License include both enterprise and commercial.
The Department has assembled an official online version of the 2010 Standards to bring together the information in one easy-to-access location.  It provides the scoping and technical requirements for new construction and alterations resulting from the adoption of revised 2010 Standards in the final rules for Title II (28 CFR part 35) and Title III (28 CFR part 36).
WAVE is a suite of evaluation tools that help authors make their web content more accessible to individuals with disabilities. WAVE can identify many accessibility and Web Content Accessibility Guideline (WCAG) errors, but also facilitates human evaluation of web content. Our philosophy is to focus on issues that we know impact end users, facilitate human evaluation, and to educate about web accessibility.
Total Validator is a validation program that comes with more than just one tool to evaluate web accessibility. In fact, the program is a 5-in-1 validation tool, including HTML and XHTML validator, an Accessibility validator, a CSS validator, a broken links checker, and, of course, a spell checker. The guidelines covered are WCAG 2.0—W3C Web Content Accessibility Guidelines 2.0, WCAG 1.0—W3C Web Content Accessibility Guidelines 1.0, Section 508, and the U.S. federal procurement standards.
Case law has been the most helpful in illuminating the implications of the ADA for websites.There have been lawsuits involving companies like Expedia, Hotels.com, Southwest Airlines, and Target as defendants and primarily featuring accessibility organizations as plaintiffs. These cases had mixed results, but each helped clarify the ADA's jurisdiction on the web.