More than 20 million US households are now receiving discounts on internet service as part of a federal program created to close the digital divide, according to the Federal Communications Commission.

The milestone highlights the cost of reliable internet service for low-income families, an issue that the government's Affordable Connectivity Program (ACP) seeks to address by providing $30-a-month subsidies to eligible US households. Recipients living on tribal lands can receive even more, up to $75 per month to help cover internet access costs.

US residents can can qualify for the program if they meet certain eligibility requirements, such as participating in other government assistance programs including SNAP or Medicaid, if their income is below a certain level or if they have recently received federal Pell grants.

The FCC announcement comes nearly two years after the bipartisan infrastructure law first set up the program, replacing an earlier pandemic-era aid initiative. And Americans have signed up for the program at a rapid pace.

In early 2022, just months after the infrastructure bill became law, the FCC said more than 10 million households had signed up for the ACP.

Then, this February, Vice President Kamala Harris announced the figure had grown to more than 16 million households saving a total of $500 million a month on internet service.

The program has continued to gain more than half a million new households a month since then.

"For a long time, closing the digital divide focused on one part of the equation—the lack of physical infrastructure to get online," said FCC Chairwoman Jessica Rosenworcel in a statement. "But we know that for many people, even when there was technically access, the cost to get online was too high."

Despite the program's bipartisan popularity and its rapid uptake by consumers, the new enrollment figures still only represent about 40% of the estimated 50 million households in the United States that may be eligible for assistance through the ACP, according to research by the consumer advocacy group Common Sense Media.

And the ACP's future is uncertain: Once the program runs out of the $14 billion that Congress initially allocated for it, millions of low-income Americans could lose their monthly discounts. The more households that sign up, the faster the program will exhaust its funding. Policy analysts widely anticipate the ACP running out of money in 2024, setting up pressure on Congress to extend the program.

The ACP isn't the only way the US government has recently moved to expand internet access. Billions of dollars in infrastructure funding are set to flow to states in the coming months as part of a separate initiative to encourage broadband buildouts. All US states and territories have been awarded at least some funding under the program overseen by the Commerce Department known as the Broadband Equity, Access and Deployment (BEAD) program.