In October, federal prosecutors slapped on another charge, known as federal programs bribery, against Loughlin for her role in the nationwide scandal dubbed "Operation Varsity Blues." She was already charged with conspiracy to commit money laundering, conspiracy to commit mail fraud and honest services mail fraud.
Her husband, fashion designer Mossimo Giannulli, was also facing the new bribery charge and asked the judge to accept his not guilty plea.
Loughlin, 54, and Giannulli, 55, also requested to waive their need to appear in court to be arraigned on the new charge later this month.
They are both among 35 other parents, including actress Felicity Huffman, who have been charged in the case. Huffman pleaded guilty to fraud and conspiracy and was sentenced to 14 days in prison. She was released after serving 11 days.
Loughlin and Giannulli are accused of conspiring with William "Rick" Singer, who federal prosecutors identified as the ringleader of the scam, to help their two daughters get into University of Southern California as crew recruits, despite not having participated in crew.
Singer emailed the couple in August 2016 saying he needed a copy of their older daughter’s transcript and test scores "very soon" and it would be good to get a photo of her "in workout clothes like a real athlete too," according to court documents.
Giannulli allegedly replied: "Fantastic. Will get all."
Singer has already pleaded guilty in a Boston federal court to charges of racketeering conspiracy, money laundering conspiracy, conspiracy to defraud the United States and obstruction of justice. He's scheduled to be sentenced on June 19.
Loughlin and Giannulli could each get a maximum 20-year prison sentence if convicted.
The new bribery charge only applied to parents like Loughlin, best known for her role in the ABC sitcom "Full House," who have pleaded not guilty to the initial indictment. The main effect of the new charge was to expose parents to additional prison time at sentencing should they be convicted.
ABC News' Kate Hodgson contributed to this report.