Scotty B. Hoover, 26, was convicted in connection with the December 2007 death of 17-year-old Greencastle High School senior Dietrich Jackson.
"The entire Hoover family and I are extremely pleased by and profoundly grateful for the judge's decision," said Michael Van Treese, Hoover's attorney.
Hoover has spent portions of his sentence at the Indiana Department of Correction, Putnam County Jail and the Indiana State Farm.
According to court documents, Hoover was made a trustee at the jail. He was never reprimanded at any facility and "did not engage in any conduct while in the custody of the Department of Correction, at any location, which was less than exemplary," court records said.
Court records also indicated that Hoover has completed phases of alcohol and drug treatment programs, and that he "has shown great and continuing remorse for his crimes, which resulted in the death of a minor child."
Including the time he spent in jail before his conviction and sentencing, Hoover had spent nearly three years behind bars -- which, with good time credit, would amount to an executed sentence of close to six years.
Van Treese filed the petition to modify Hoover's sentence in mid-October. A hearing was held on the matter on Dec. 2, and Judge Matthew Headley granted the petition and ordered Hoover released on Wednesday.
At the Dec. 2 hearing, Hoover said he could work for his father's painting business, and that he was considering relocating to Jacksonville, Fla. to work with his sister's husband in his landscaping business.
Charity Pankratz, Jackson's grandmother, told Headley she believed Hoover had been in jail for long enough. Pankratz and Jackson's mother, Treva Jackson, testified at Hoover's sentencing in 2008 and requested leniency.
Treva Jackson had also filed letters with the court, asking that Hoover be released from jail.
The state did not take a position on the petition. Hoover will remain on probation for the rest of his sentence. He was also ordered to submit to random drug testing. Attend Narcotics Anonymous meetings at least once a week and get a job.
Dietrich Jackson died after overdosing on prescription drugs. Hoover provided some of the drugs -- Xanax and oxymorphone -- that led to the teen's death.
Court records said Hoover crushed pills so Jackson could snort them.
Putnam County Coroner Thomas Miller said the oxymorphone, which is six to eight times more potent than morphine, was likely the cause of Jackson's death.
Hoover received 13 years for the Class B felony and 5 years for the Class C, with the two to run concurrently. He had credit for 341 days he served at Putnam County Jail before he was sentenced.
Headley sentenced Hoover to 13 years with nine executed in prison, two years on probation and two on home electronic detention.
The state recommended the maximum sentence for Hoover -- 28 years.
At his sentencing, Hoover apologized to Jackson's family, and told the court that he had considered the boy a friend.