The extension beyond this June comes as Comcast seeks approval for its $45 billion purchase of Time Warner Cable, which will extend its lead as the nation's top pay TV and Internet access provider.
Regulators are expected to spend around a year reviewing the deal.
Philadelphia-based Comcast Corp. plans to list the program's extension as one of the deal's benefits.
It also pledged $1 million in grants to non-profit organizations to help pay for computer literacy sessions, buy computers and set up Wi-Fi hotspots.
Comcast's Internet Essentials has so far connected 300,000 low-income homes with Internet access for $10 a month.