Oats had spent the past two seasons as an assistant for the Bulls. He previously coached at Romulus (Mich.) Senior High School.
"After hours of conversations with Nate, it became very clear to me that the best candidate to lead our men's basketball team was already on campus," Athletic director Danny White said in a news release. "Nate has tremendous experience as one of the finest coaches in America at both the collegiate and high school levels, and played an absolutely critical role in elevating our program to the NCAA Tournament, for the first time ever, in just two years.
"I am extremely confident that UB men's basketball will continue to grow and reach new heights under Nate's leadership. To be sure, Alumni Arena will be an electric environment again next year as these talented student-athletes fight to defend their Mid-American Conference Championship!"
This season Buffalo recorded 23 wins and won the MAC conference tournament to earn the program's first tournament berth.