This partnership laid the foundation for a merger with Adriko and Karugaba Advocates and Central Law Office to form MMAKS Advocates a top tier law firm in Uganda. He retired from legal practice and mainly spends time between his farm and lakeside property in Mukono District and ranch in Kyankwazi District   He also reentered public life when Kabaka Ronald Mutebi appointed Nkambo Mugerwa to be the chairman of the Buganda Land Board, taking over for James Mulwana who had to resign after an "operation weakened" him. He oversaw a 13-person board, including Prince David Kintu Wassajja, Kabaka Mutebi's younger brother, the Luweero district chairman, Hajji Nadduli Kibaale and Martin Kasekende, the managing director of National Housing and Construction Company. He served in this role until 2007, when Martin Kasekende replaced him. Peter James Nkambo Mugerwa is an active member of the Uganda Mountain Club, and enjoys mountaineering, whitewater kayaking, rock climbing, hiking, backpacking, and biking. He has a son, Michael Nkambo Mukerwa, who is a general manager at  Uganda Refinery Holding Company, a subsidiary of Uganda National Oil Company, as of the 29 May 2019.