Lantz, Donald J., age 83, passed away surrounded by his loving family on Sunday, December 6, 2015. Most recently a Quincy resident, Mr. Lantz formerly resided in Largo FL and had lived in Milton for many years. He was a graduate of Eastern Nazarene College and attended Harvard Divinity School. The former owner and Medical Director of Beacon Medical Laboratories, he also was the former co-owner of Roxbury Medical Lab of Boston and Northeast Medical Lab, Haverhill. Mr. Lantz was the Past President of MA Association of Independent Laboratories and a former consultant of Medicare Legislation for U.S. Government. He was an avid skier and taught all his children and grandchildren how to ski. He traveled worldwide with his late wife. The beloved husband of the late Marie A. (MacDonald), he was the devoted father of Cindie Lally & her husband Jim of Quincy, Donald J., Jr. & his wife Jo-an of Milton, Laurie Lantz Flaherty of Conway, NH and Sandie Deveney & her husband Donald of Middleboro and is survived by 20 cherished grandchildren & 2 great grandchildren. He was the brother of the late Gloria Xavier. A Funeral Service will be held at the Alfred D. Thomas Funeral Home, 326 Granite Ave., Milton, Thurs. morning at 11. Visiting hours Wed. 2 to 4 and 6 to 8 PM. Interment private. In lieu of flowers expressions of sympathy may be made to Dana Farber Cancer Institute, P.O. Box 849168, Boston, MA 02284 – 9168.