The award, reached Friday by an Essex County jury, was given to Jadiel Velesquez, who lawyers said suffered severe brain damage in the alleged beating.
Jadiel's grandparents sued DYFS, accusing the agency of failing to remove the boy from his home after he was brought to the hospital with unexplained bruises. The grandparents claimed they were inflicted by the boy's father.
Lawyers said the boy was returned to his mother's home despite a doctor's finding of abuse. The beating that left him dependent on 24-hour-care happened weeks later.
In a DYFS memo given to staff, Commissioner Alison Blake said the agency is reviewing the verdict with lawyers to see if it will appeal. Blake said she is hurt and angry about the case.
She said the state's child welfare system has undergone major reforms, including reducing caseworker workload and strengthening training and supervision of caseworkers.
Jadiel's father pleaded guilty to beating his son and is serving a six-year prison term for aggravated assault, lawyers said.
Lawyers for the grandparents say it is the largest personal injury verdict in New Jersey history, and the largest verdict against a child protective services agency in the nation's history.
They say Jadiel, born healthy, now cannot walk or talk. He is blind and needs the care of nurses and doctors around the clock.
The victim's grandmother, Noemi Escobar, believes the verdict has wider implications.
"They did justice," she said. "They need to be more careful with kids like Jadiel. They put in danger and are at risk with parents or other people that treat them bad. So they need to take care of them. They have the power, so they better do it."
The Associated Press contributed to this report.