Former Georgia governor and U.S. Sen. Zell Miller is now officially retired from public life.

According to Bryan Miller, executive director of the Miller Institute for Public Policy in Atlanta and Zell Miller's grandson, Miller has a form of Parkinson’s and is receiving treatment and physical therapy at his home in Young Harris where he lives with his wife of 63 years, Shirley Miller.

Miller started becoming aware of symptoms in February 2016 after a fall.

Bryan Miller said his grandfather, who turns 86 next February, has good days and bad days. He’s talking and engaged with family life. He has trouble walking so he uses a wheelchair.

PHOTOS: Zell Miller retires from public life

Bryan Miller created the Institute to preserve and promote the legacy of his grandfather’s life in government and politics, and to train new generations of public servants to move Georgia forward the way his grandfather did.

What does Zell Miller consider his greatest accomplishment?

Not the lottery-funded HOPE scholarship and Pre-K program, which is his crowning achievement, politically. But his family: sons, grandchildren and his marriage to Shirley, who Zell Miller said is his biggest single supporter and critic and who is responsible for all he accomplished while in office.