Section 508 of the Rehabilitation Act of 1973 does not specify the requirements for choosing an accessible website typeface.
The creation of experiences that work for as many users, potential users, users with disabilities is very important. Typography plays a major role in the larger accessibility picture and should be chosen and then executed carefully in a way that creates an experience all users can participate with.
While Avondale Type Co. cannot say that any fonts we, or others have created are “certified as ADA compliant” as this does not exist (only guidelines around selection and usage), we have have created ATC Arquette to follow guidelines and best practices for an ADA recommended font, similar to Arial, or Verdana.
ATC Arquette has been design as simple, unadorned and without decoration. Usage of this font should always utilize best practices for ADA compliance when it comes to typography. For usage information please read the license agreement for our typefaces as well as our FAQs.
There are very good resources regarding ADA compliance and fonts.
The Bureau of Internet Accessibility has shared a few important notes.
Currently, Section 508 of the Rehabilitation Act of 1973 does not specify the requirements for choosing an accessible website typeface. However, the US Department of Health & Human Services unofficially recommends the following fonts for PDF files: Times New Roman, Verdana, Arial, Tahoma, Helvetica, and Calibri.
What do the above fonts all have in common? For one, they’re all basic, simple, and unadorned, with no extra decorations or flourishes. What’s more, they usually come automatically installed on computers. When all else is equal, designers should always choose a more popular font over a less popular alternative. This will increase the likelihood that the user’s computer can display it.
Although serif fonts are usually preferred for printed items, such as books and newspapers, the opposite holds true for websites. Proportionally, the “ticks” and “tails” of serif fonts take up a larger amount of space on a screen than they do on a printed page. In general, sans serif fonts display better on computers and mobile devices.
Above all, avoid decorative or overly stylized fonts, which are often difficult to read even for users without visual impairments or reading disabilities.
You can read more about Fonts and Internet Accessibility here.