He skirted jail when a juvenile court in 2014 sentenced him to 10 years of probation, sparking public outrage.
A psychologist testifying for the teen said Couch was suffering from what he called "affluenza".
"From the beginning, Ethan has admitted his conduct, accepted responsibility for his actions, and felt true remorse for the bad consequences of those actions", they said, adding that he will serve the remaining six years of his community supervision under the terms imposed by the court.
Couch was 16-years-old in 2013 when he caused a crash that killed four people and left a fifth paralyzed. Later that night, Couch, who had a Blood Alcohol Level of.24 (nearly three times Texas' legal limit), Couch and some friends piled into his father's pickup truck.More news: Israel and UN Reach Deal to Deport African Migrants to West
More news: Chinese space station expected to crash back to Earth this weekend
More news: Raises For Oklahoma Teachers May Not Be Enough To Stop A Strike
Couch left the Tarrant County Detention Center around 9 a.m. and was immediately taken to the county's adult probation office to be fitted with an ankle monitor. The fiasco resulted in Couch and his mother taking off for Mexico, staying on the run for weeks, and finally captured in December 2015 after using a cellphone to order Domino's pizza. "From the beginning, Ethan has admitted his conduct, accepted responsibility for his actions, and felt true remorse for the awful consequences of those actions".
They were found in the resort town of Puerto Vallarta, and flown back to the United States were the teenager was ordered to jail for 720 days. Couch's probation was revoked in 2016 after he attended a party where alcohol was served.
Ethan Couch was extradited back to the USA and later sentenced to 720 days in jail for violating the terms of his probation. He was extradited and later sentenced to 720 days in jail for the violation.
She was just returned to jail last week after failing a drug test, NBC 5 said.
No time has been set for his release, but the sheriff's office for the county, which includes Fort Worth, begins processing inmates at 8 a.m. (1300 GMT), office spokesman David McClelland said.
A spokesperson for Mothers Against Drunk Drivers told CNN that Couch's case was a "grave injustice".