Alamilla, of Lincoln, was previously convicted of motor vehicle homicide, being a habitual criminal, refusal to test, and obstruction of an officer.
Judge James Livingston sentenced Alamilla to 18-20 years on the motor vehicle homicide charge. As part of that charge, prosecutors said Alamilla was driving under the influence.
He was also sentenced to prison on the remaining charges, but those will be served at the same time.
Jerry Ray Ramirez, of Grand Island, was killed in the crash on Highway 281 in August.
According to the Hall County Sheriff's Department, the 29-year-old Ramirez died after being ejected from the vehicle he was riding in as it rolled across the median about a half mile north of Guenther Road. Officials say he was not wearing a seatbelt.
Witnesses say Alamilla was driving the southbound Cadillac. It appeared Alamilla lost control of the car and entered the median, where it then rolled until coming to a stop in a northbound lane.
In court, prosecutors have said Alamilla was weaving on the highway while shouting obscenities at traffic.
He then allegedly lost control, went through the median, and rolled the Cadillac. Two passengers were ejected.
The car was then struck by a 2008 Chevy Silverado driven by 26-year-old Grand Island woman, who was not injured in the accident.