An internal combustion engine is fluidly coupled to an exhaust aftertreatment system including a particulate filter. A method for operating the internal combustion engine includes determining an expected boost pressure of an intake air compressor system in response to an output torque request, determining a deviation between an actual boost pressure and the expected boost pressure, determining a engine-out soot generation rate correction based upon the deviation between the actual boost pressure and the expected boost pressure, adjusting a steady-state engine-out soot generation rate using the engine-out soot generation rate correction, time-integrating the adjusted steady-state engine-out soot generation rate, and commanding regeneration of the particulate filter when the time-integrated adjusted engine-out soot generation rate exceeds a predetermined threshold.