ADA website-accessibility standards have not been issued by the federal government. In 2010, the US Department of Justice (DOJ) announced that was considering issuing regulations applying the ADA to websites. Originally, it was expected that DOJ would issue website-accessibility standards for places of public accommodation by the spring of 2014,  but the DOJ has now delayed issuing those regulations until 2018.
Many have anticipated that ADA website-accessibility rules, if and when they are issued, will resemble the standards set forth in the Web Content Accessibility Guidelines (WCAG), which are promulgated by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium.  As described by the DOJ, the “WAI has created recognized voluntary international guidelines for Web accessibility” which “detail how to make Web content accessible to individuals with disabilities.”