The former "Jersey Shore" star, 35, pleaded guilty to tax evasion, while Marc Sorrentino, 38, admitted to the "aiding in the preparation of a false and fraudulent tax return", according to a news release from the United States Attorney for the District of New Jersey.
Sorrentino, 36, will have to pay $123,000 in restitution, Klingeman said.
Sorrentino "walked into the Newark court with his girlfriend, Lauren Pesce, and entered his guilty plea as expected".
Michael Sorrentino on Friday pleaded guilty to one count of tax evasion for deliberately concealing some of his income in 2011 by making cash deposits in amounts of less than $10,000 so they wouldn't trigger federal reporting requirements.
Federal prosecutors accused the siblings of falsifying tax records on $8.9 million in earnings following a 2014 indictment for other tax-related offenses.
The lawyer for Michael "The Situation" Sorrentino says the "Jersey Shore" reality TV star shouldn't serve jail time for cheating on his taxes.
Authorities accused the brothers of evading the Internal Revenue Service by filing false tax returns, underreporting their income and mixing personal and business bank accounts, using the money from business bank accounts for personal items such as luxury vehicles and clothing.
They were charged in 2014 and again a year ago with multiple counts related to almost $9 million in income from the show.
The Sitch's charge carries a maximum penalty of five years behind bars. If convicted, Mike faces up to 15 years in prison; Marc faces up to 25.
In a statement to The Blast, Mike Sorrentino's attorneys said that he made mistakes at a "very different and tumultuous time in his life" and that he "deeply regrets his failure to pay his taxes". Joe Giudice also pleaded guilty to not paying about $200,000 in income taxes.
In a 30-minute special for E! that aired in August, "Reunion Roadtrip: Return to the Jersey Shore", Michael Sorrentino was asked about the allegations against him by fellow castmate Nicole "Snooki" Polizzi.
He is scheduled to be sentenced in late April.
The U.S. attorney's office filed additional charges last April.