Mahaffey earned a bachelor of architecture degree, with honors, from the University of Oklahoma, where he has since established the Mary and Michael Mahaffey Architectural Scholarship. After three years of apprenticeship in both Oklahoma and Colorado, he was licensed by examinations in Oklahoma in l964, Texas in l966, Colorado in l982, New Mexico in l983, South Carolina in l995, Arizona in l995 and Pennsylvania in l995. He also holds a certificate from the National Council of Architectural Registration Boards. Michael Mahaffey has been in continuous architectural practice since 1966 with offices in Oklahoma City & Santa Fe, New Mexico. His practice includes projects in Oklahoma, the desert Southwest, the Rocky Mountains, the Pacific Coast, and Manhattan.
Mahaffey has received an Excellence of Design Award from the Oklahoma Blood Institute, the City Scape Award for Doctors Medical Plaza, the Bentley Mills Award of Excellence for the Raymond Young Conference Center at Baptist Medical Center, and an Appreciation Award from the Comanche Indian Tribe in Oklahoma. In August, l99l, he was named one of the world's top l00 architects by Architectural Digest. His work has been featured in Architectural Digest, Southern Living, Oklahoma Home and Garden, and Oklahoma Home & Lifestyle.
Mahaffey serves or has served on the boards of the Episcopal Diocese of Oklahoma, St. Paul's Episcopal Cathedral, the Arts Council of Oklahoma City, the Lyric Theatre, the Nichols Hills Board of Adjustment, the University of Oklahoma Board of Visitors, the Oklahoma County Mental Health Association, Southwestern Association for Indian Arts SWAIA, New Mexico Governors Mansion Foundation Board and on the Overholser Mansion Advisory Committee. In addition, he is a former chairman of the Spring Festival of the Arts and former treasurer of the Oklahoma Republican Party.