WASHINGTON — Regulators are preparing to offer low-income Americans a significant new discount on Internet service – $9.25 a month – setting the stage for an explosion in broadband adoption among the poor. If it works, millions of underprivileged people could soon gain greater access to what has become a vital tool for modern economic growth.

“We’re talking about real people,” said FCC Commissioner Mignon Clyburn in an interview. “These are the people who need broadband the most – and they are on the wrong side of the digital divide.”

The proposal from the Federal Communications Commission would overhaul the nation’s approach to communications subsidies, shifting decisively away from traditional phone access and prioritizing high-speed Internet instead.

It would revamp an existing program known as Lifeline, which currently gives $9.25 a month to eligible households to spend on telephone service. Changes to the program would allow Americans to spend the subsidy on fixed, wired broadband as well as cellular data plans – which they previously have not been able to do. It would even allow low-income customers to apply the discount toward bundles of fixed and mobile Internet service.

Wired Internet providers that take Lifeline customers would be required to provide them with download speeds of at least 10 Mbps and upload speeds of at least 1 Mbps, according to the proposal. Cellular service providers, meanwhile, will be expected to give Lifeline subscribers 500 MB of data at 3G speeds to start – a figure that would gradually rise to 2 GB by the end of 2018.

Wealthier populations have migrated online with relative ease. But the poor have largely been left behind, said FCC Chairman Tom Wheeler and Clyburn in a blog post Tuesday.

“Internet access has become a pre-requisite for full participation in our economy and our society,” they wrote, “but nearly one in five Americans is still not benefitting from the opportunities made possible by the most powerful and pervasive platform in history.”

Agency officials frequently cite the lack of broadband as a major impediment to economic growth, particularly among the poor.

Reports of low-income children relying on public WiFi at fast-food restaurants for their homework needs has led to what FCC Commissioner Jessica Rosenworcel calls a “homework gap” prevent- ing poorer school kids from catching up with their richer peers.