Multiple divisions entered 2026 with recent title shifts driven by upsets and injuries, including Justin Gaethje claiming the interim lightweight belt, Sean Strickland regaining the middleweight title via upset over Khamzat Chimaev, and Carlos Ulberg capturing light heavyweight gold. Current undisputed champions such as Tom Aspinall (heavyweight), Islam Makhachev (welterweight), and Alexander Volkanovski (featherweight) face defenses or unification bouts amid a packed second-half schedule. Factors like fighter inactivity, potential rematches, and emerging contenders from recent cards shape implied probabilities, with heavyweight interim situations adding volatility to unification outcomes. Roster health and matchup styles remain key variables for any new titleholders by year-end.