Turbine airflow is modulated to improve performance during part load operation in a turbomachine. The turbomachine includes a compressor, a turbine with a plurality of stages, and a diffuser. Modulating the airflow includes extracting airflow from an upstream component of the turbomachine, admitting the extracted airflow into a rear stage of the plurality of stages. Admitting airflow into the rear stage serves to increase rear stage loading and alter an energy distribution in the rear stage during part load operation.