A powertrain system includes an engine coupled to a transmission operative in one of a plurality of operating range states to transfer power between the engine and an output member. A method for controlling the powertrain system includes monitoring an operator torque request, monitoring barometric pressure and engine input speed to the transmission, determining an achievable range of input power transferable from the engine to the transmission based upon the barometric pressure and the engine input speed, and determining a preferred operating range state for the transmission and a preferred engine operating point at the preferred operating range state based upon the operator torque request and the achievable range of input power.