This report is an update of the original Part IV of the Rotor-bearing Dynamics Design Technology Series, AFAPL-TR-65-45 (Parts I through X). A Computer program is given for preparation of ball bearing stiffness data input for rotordynamic response programs. The complete stiffness matrix is calculated including centrifugal effects. Considerations such as elastohydrodynamic and cage effects are not included since they have little influence on the calculation of ball bearing stiffness. The resulting program is reasonably small and easy to use. Lastly, the stiffness data included in the original Part IV have been updated and are included in appendices.