A combustor for a gas turbine engine operates with high combustion efficiency and low carbon monoxide, nitrous oxide, and smoke emissions during low, intermediate, and high engine power operations is described. The combustor includes a mixer assembly including a pilot mixer, a main mixer, and a mid-power and cruise mixer. The pilot mixer includes a pilot fuel injector, at least one swirler, and an air splitter. The main mixer extends circumferentially around the pilot mixer. The mid-power and cruise mixer extends between the main and pilot mixers and includes a plurality of fuel injection ports which inject fuel radially inwardly to facilitate radial and circumferential fuel-air mixing to provide a substantially uniform fuel and air distribution for combustion.