He was 80 years old.

Michael Reagan was adopted by Ronald Reagan and his wife Jane in 1945.

"It is with great sadness that we announce the passing of Michael Edward Reagan," Reagan's family said in a statement on Tuesday.

"Michael was and will always remain a beloved husband, father, and grandpa. Michael was called home to be with the Lord on Sunday, January 4th, surrounded by his entire family in Los Angeles, California," the family said.