The 6-foot-4½, 295-pound Hegarty had overcome a stroke in 2012 to become a regular on the Fighting Irish's offensive line, starting 11 of 13 games last season at center and guard.
The Aztec, New Mexico, native is expected to graduate in May. He would be eligible to play at another school this coming season.
"I am extremely grateful for the opportunity that the Notre Dame Football program has afforded me," Hegarty said. "I want to thank Notre Dame, my coaches, my teammates and friends at school for the four great years I had at Notre Dame. I also want to thank the Notre Dame Nation for all of their support over the years. My focus has been to pour myself into everything that I have done at ND. I have worked hard and have always done everything that was asked of me. Recently my coaches informed me that they wanted me to change positions. They also explained that with many younger players in the wings, they wanted to develop them more heavily in the rotation -- a need that I understand and appreciate.
"Unfortunately, I have already had to miss a precious amount of football battling back from my stroke, and I value every rep and opportunity going into my final year of college ball that much more. My goal is to contribute this season, continue to develop my skills and pursue my dream of playing in the NFL. Because of this goal, I have asked for a transfer to play at another school where I can contribute more on the field. Notre Dame has amassed formidable depth on the O-line and have many very talented players to fill all positions.
"So I wish everyone at ND the best this year and especially to my 15 brothers on the offensive line as they prepare for the 2015 season."
The Irish still return four of five offensive line starters from their Franklin American Mortgage Music City Bowl win over LSU in December.