The following information is reposted from the FCC:
On January 12, 2012, the FCC adopted rules requiring captioned programs shown on TV to be captioned when re-shown on the Internet. These rules implement provisions of the Twenty-First Century Communications and Video Accessibility Act of 2010 (CVAA).
Starting September 30, 2012, pre-recorded programs shown on TV with captions that are not “edited for the Internet” (and are newly added to a distributor’s inventory of TV programs on the Internet) must be captioned when shown on the Internet. A program is not “edited for the Internet” if the TV version has not been “substantially edited” – for example scenes were not deleted and musical scores were not altered. Changing the number or duration of commercials is not considered “edited for the Internet.”
Other kinds of captioned TV programs – such as programs that are shown live on TV – must be captioned at a later date.
For more information, see the FCC Consumer Guide: Captioning of Internet Video Programming:
Read more about closed captioning requirements in Sam Joehl’s February 2012 post, U.S. Captioning Requirements, on the SSB BART Group blog.