Janavs, whose family developed the wildly popular microwaveable snack before selling their company, had earlier pleaded guilty to conspiracy to commit wire fraud and conspiracy to commit money laundering in the far-reaching college admissions scandal.
The 49-year-old Newport Beach, California, resident admitted that she pledged $300,000 to fixer Rick Singer for help in fraudulently boosting college qualifications of her two daughters.
U.S. District Judge Nathaniel Gorton also ordered Janavs to pay a $250,000 fine and be subject to two years supervised release after she's freed from prison.
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She gave Singer $100,000 to have a proctor correct ACT exam answers for one daughter. Janavs also agreed to pay $200,000 to have another daughter passed off as a star beach volleyball recruit, though the mom was arrested before the girl could be admitted to USC, prosecutors said.
The judge ordered her to report to prison April 7, NBC Boston reported.
"I'm so very sorry I tried to create an unfair advantage for my children," Janavs told the court Tuesday.
Prosecutors had asked for 21 months.
Defense lawyers said their client is a dedicated mother and a philanthropist who fell for Singer's "manipulative sales tactics." The defense has said Janavs has already been punished enough with public embarrassment and shouldn't be sent to prison.
"The fallout from Michelle's actions stand as a beacon to others that illegal shortcuts are a recipe for disaster, regardless of the punishment the court imposes on Michelle," her lawyers wrote.
Janavs is among dozens of affluent parents involved in the massive cheating scandal, which also swept up "Desperate Housewives" star Felicity Huffman and "Full House" actress Lori Loughlin.
Huffman was released in October after serving about 11 days of a 14-day sentence.
Loughlin and her fashion designer husband, Mossimo Giannulli, who are accused of paying $500,000 to get their daughters into USC, are still fighting their charges.