The coach explained his decision in a statement:
"I have informed Mr. [Robert] Kraft and Coach [Bill] Belichick that I am stepping down from my position at the Patriots. This is not the result of any one event, but rather a realization that I need to spend more time on my faith and family. I don't want to look back years from now and wish I had done things differently. Therefore, I am taking time away from the game to recalibrate my priorities."
Schiano was hired by the team in February after spending the past three years as the defensive coordinator at Ohio State.
Schiano, who had been a head coach with Rutgers and the Tampa Bay Buccaneers, was effectively replacing Brian Flores on the staff after the linebackers coach left for the Miami Dolphins. Flores called the defensive plays last season, although he was not officially known as the defensive coordinator.
A positive relationship with Patriots head coach Bill Belichick over the years likely helped Schiano get the position.
However, the 52-year-old will now leave the organization before the start of his first season.
The move is especially surprising considering the Patriots recently added one of his longtime assistants, Bob Fraser, per Kevin Duffy of the Boston Herald. Fraser had spent time working on staff with Schiano at each of his last three stops and was hired by New England on Tuesday.
Still, it was not enough to keep the defensive coordinator on staff.
"I respect Coach Schiano greatly and appreciate his contributions to our staff and team. He is a friend who we support completely," Belichick said in a statement.