In 2017, the United States Access Board published a final rule updating information and communication technology covered by Section 508 of the Rehabilitation Act and section 255 of the Communication Act. Some relevant articles from the US Government include:
The refresh puts US Government requirements in alignment with Web Content Accessibility Guidelines, which are the globally-recognized voluntary standards for web content and information and communication technology.
Essentially, when a federal governmental organization wants to purchase software, they are required to ensure that the software meets accessibility standards as defined by the Web Content Accessibility Guidelines for Level A and Level AA guidelines. They identify which products meet their criteria using a Voluntary Product Accessibility Template (VPAT).
It is in the government’s best interest to buy software that can be used by anyone regardless of disability.