A compound comprising a ligand LA coordinated to a metal M, the ligand LA selected from the group consisting of Formula I, Formula II, and Formula III ring A is a 5- or 6-membered carbocyclic or heterocyclic ring; wherein ring A of Formula I connects to ring B at X1, X2, or X3 to form a five-membered chelate ring with the metal; Z1 and Z2 are independently selected from C or N; and X1 to X10 are independently selected from C or N. An organic light emitting device (OLED) comprising an anode, a cathode and an organic layer disposed between the anode and the cathode, the organic layer comprising a compound selected from Formula I, Formula II, or Formula III, and a consumer product comprising the OLED.