An American woman admitted to helping kill her mother and pack her body in a suitcase in 2014 while on a lavish vacation at a Bali resort.
In Indonesia, Heather Mack, now 27 years old, was found guilty in 2015 and given a 10-year prison term; however, she was released in 2021.
She was detained as soon as she landed in the country and accused of obstructing justice and plotting the murder of an American citizen.
A lengthy prison sentence awaits Ms. Mack.
When she was sent back to the US in November 2021, she initially pleaded not guilty to the charges.
Prosecutors stated in court documents that the charges against her do not violate laws prohibiting the prosecution of a person twice for the same crime, in part because the US has charged her with conspiracy, which was not involved in the Indonesian case.
The trial was scheduled to start on August 1. On December 18, she will now receive a sentence. An up to 28-year sentence is stipulated in the agreement made for her change of plea.
Sheila von Wiese-Mack, a wealthy academic, was murdered, and Ms. Mack and her then-boyfriend Tommy Schaefer were found guilty in Indonesia of being complicit in the crime.
The two allegedly attempted to access a $1.5m (£1.17m) trust fund.
Ms. Mack, who was pregnant and only 18 years old at the time, was allegedly seen covering her mother's mouth as Mr. Schaefer struck her in the head with a fruit bowl. Later on, a suitcase containing her was found.
Mr. Schaefer, who is also mentioned in the US indictment, is still being held captive in Indonesia.
Some members of Ms. Mack's family had complained that her initial sentence in Indonesia was too lenient. She received a lighter sentence, according to the three-judge Indonesian panel, because she had just given birth to a child.
