Huffman, who is married to actor William H. Macy, arranged for her daughter to be granted extra time for her SAT exam by having her certified as having a learning disability.
Athletic coaches from Yale, Stanford, USC, and Georgetown, among others, were also implicated as well as parents and exam administrators, federal prosecutors said.
The schools themselves are not targets of the investigation, he said, and no students were charged.
A law enforcement source confirms to CNN that Huffman was arrested in Los Angeles.
The world of college sports, extremely rich people, and shady business practices intersected in a magnificent way on Tuesday as federal prosecutors announced charges filed against 50 individuals in a massive college entrance fraud ring.
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The payments ranged from $200,000 to $6.5 million, according to Andrew Lelling, the United States attorney in Boston, Massachusetts where the case was filed.
Lelling said, via CNN: "This case is about the widening corruption of elite college admissions through the steady application of wealth combined with fraud".
From 2011 through February 2019, parents paid an admissions consultant $25 million to bribe coaches and other administrators so their kids would get in.
They said fake athletic profiles were also made to make students look like strong high school athletes when they actually weren't.
Wealthy parents paid Singer up to $75,000 for "someone to take the test for their child or correct the exam afterward", Lelling said.
Officials claimed to have obtained emails from Loughlin supporting their case.
This was either a coach, who would falsely admit the student as an athlete, or an administrator of the SATs or ACTs. Loughlin's husband, fashion designer Mossimo Giannulli, was charged with the same felony as well as honest services mail fraud.