A turbine blade with a 5-pass serpentine flow cooling circuit for mid-blade cooling that is formed from a 3-pass forward flowing serpentine circuit followed by a 2-pass aft flowing serpentine circuit with the first leg or supply channel for the circuit located between the second leg and the fourth leg. A crossover channel connects the third leg to the fourth leg and passes underneath the blade tip to provide convective cooling and also discharges cooling air through tip cooling holes.