The invention relates to a method for assessing the operability of a catalytic converter (7) mounted in the exhaust gas system (6) of an internal combustion engine (1). The inventive method comprises the following steps: recording the signal (USHK) of an exhaust gas probe (9) situated behind the catalytic converter; forming a limit value model amplitude (AHKF) from at least one quantity (ML, n) occurring upstream from the catalytic converter (7); forming a catalytic converter assessment quantity (DKATI) whose value increases with a growing difference of the amplitude (AHK) of the signal (USHK) from the limit value model amplitude (AHKF); assessing the operability of the catalytic converter (7) based on the catalytic converter assessment quantity (DAKTI), and; ceasing the assessment when an oxygen-dependent catalytic converter load (KATIN) exceeds or falls below a threshold value. The method is characterized in that the threshold value is predetermined according to the signal (USHK) of the exhaust gas probe (9) situated behind the catalytic converter.