SSPL / Getty Images Maybe the federal government paid the bill for some of these phones.

Last year, a federal program paid out $1.6 billion to cover free cell phones and the monthly bills of 12.5 million wireless accounts. The program, overseen by the FCC and intended to help low-income Americans, is popular for obvious reasons, with participation rising steeply since 2008, when the government paid $772 million for phones and monthly bills. But observers complain that the program suffers from poor oversight, in which phones go to people who don’t qualify, and hundreds of thousands of those who do qualify have more than one phone.

Last summer, a Pittsburgh Tribune-Review story shed some light on a government program that relatively few Americans knew existed. (Read more about it here.) The Lifeline program provides low-income Americans with free cell phones (basic ones such as those made by Tracfone, not smartphones) and covers up to 250 free minutes each month. As many as 5.5 million residents in Pennsylvania alone could qualify for the program, which is funded primarily by the Universal Service Fund fee added to the bills of land-line and wireless customers.

The program came to be after the Telecommunications Act of 1996 was passed, and the FCC created the Universal Service Fund to help “to promote the availability of quality services at just, reasonable, and affordable rates,” among other things. All telecommunications carriers must pay into the fund, and many do so by tacking on a fee to each of their customers’ bills. It’s probably added into your monthly wireless bill and your landline bill, if you still have one.

The Universal Service Fund provides discounts on phone services, or in some cases, entirely free services to low-income Americans. The fund helps pay for landlines or cell phones, whichever the recipient prefers. There’s also a one-time discount of up to $30 to cover an installation fee or a cell phone. Considering how cheap some cell phones are nowadays, the money more than covers the costs of a basic phone. Then, the fund covers phone bills to the tune of $10 a month, which typically translates as 250 minutes for wireless plans of the types of phones we’re talking about. Americans who receive food stamps, Medicaid, or other federal aid, or who earn up to 135% of the federal poverty guidelines, qualify for the program.

Now, Bloomberg Businessweek reports, we have a pretty good idea of how much the program pays out—and how quickly it’s growing as more and more people find out about it. In 2011, Lifeline paid out $1.6 billion, more than double the amount paid in 2008 ($772 million).

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What’s more, an FCC audit of the program last year showed that many participants in the program were taking more than their fair share. According to Businessweek:

269,000 wireless Lifeline subscribers were receiving free phones and monthly service from two or more carriers.

Senator Claire McCaskill (D-Mo.) has been taking a closer look at the program since she personally received an invitation to apply for a free, government-subsidized cell phone in the mail. McCaskill has asked the FCC to investigate Lifeline. As a result, the FCC is building a database to see if a subscriber has more than one subsidized phone. In other words, until recently, such a database didn’t exist.

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The FCC, which announced the changes by using the euphemism that it is “modernizing” Lifeline, has set a goal of saving $200 million on the program in 2012. After eliminating nearly 270,000 of the duplicate subscriptions discovered in the audit last year, the FCC said it has already “saved” $33 million.

Brad Tuttle is a reporter at TIME. Find him on Twitter at @bradrtuttle. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.