An extra-cardiovascular implantable cardioverter defibrillator comprising: a high voltage therapy module including: a high voltage capacitor having a first capacitance; a high voltage charging circuit configured to charge the high voltage capacitor; and first switching circuitry configured to couple the high voltage capacitor across extra-cardiovascular electrodes (24A, 24B, 28A, 28B, 30) coupled to the ICD; a low voltage therapy module including: a plurality of low voltage capacitors (612, 614, 616, 618) each having up to a second capacitance that is less than the first capacitance; a low voltage charging circuit configured to charge the plurality of low voltage capacitors; and second switching circuitry configured to selectively couple the plurality of low voltage capacitors to the extra-cardiovascular electrodes coupled to the ICD; and a control module coupled to the high voltage therapy module and the low voltage therapy module and configured to: control at least one of the low voltage therapy module or the high voltage therapy module to perform a capture threshold test, based on the capture threshold test, select a pacing output configuration from among at least a low-voltage pacing output configuration of the low voltage therapy module and a high-voltage pacing output configuration of the high voltage therapy module; control a respective one of the low voltage therapy module and the high voltage therapy module to deliver extra-cardiovascular pacing pulses in the selected one of the low-voltage pacing output configuration or the high-voltage pacing output configuration via the extra-cardiovascular electrodes. a high voltage therapy module including: a high voltage capacitor having a first capacitance; a high voltage charging circuit configured to charge the high voltage capacitor; and first switching circuitry configured to couple the high voltage capacitor across extra-cardiovascular electrodes (24A, 24B, 28A, 28B, 30) coupled to the ICD; a high voltage capacitor having a first capacitance; a high voltage charging circuit configured to charge the high voltage capacitor; and first switching circuitry configured to couple the high voltage capacitor across extra-cardiovascular electrodes (24A, 24B, 28A, 28B, 30) coupled to the ICD; a low voltage therapy module including: a plurality of low voltage capacitors (612, 614, 616, 618) each having up to a second capacitance that is less than the first capacitance; a low voltage charging circuit configured to charge the plurality of low voltage capacitors; and second switching circuitry configured to selectively couple the plurality of low voltage capacitors to the extra-cardiovascular electrodes coupled to the ICD; and a plurality of low voltage capacitors (612, 614, 616, 618) each having up to a second capacitance that is less than the first capacitance; a low voltage charging circuit configured to charge the plurality of low voltage capacitors; and second switching circuitry configured to selectively couple the plurality of low voltage capacitors to the extra-cardiovascular electrodes coupled to the ICD; and a control module coupled to the high voltage therapy module and the low voltage therapy module and configured to: control at least one of the low voltage therapy module or the high voltage therapy module to perform a capture threshold test, based on the capture threshold test, select a pacing output configuration from among at least a low-voltage pacing output configuration of the low voltage therapy module and a high-voltage pacing output configuration of the high voltage therapy module; control a respective one of the low voltage therapy module and the high voltage therapy module to deliver extra-cardiovascular pacing pulses in the selected one of the low-voltage pacing output configuration or the high-voltage pacing output configuration via the extra-cardiovascular electrodes. control at least one of the low voltage therapy module or the high voltage therapy module to perform a capture threshold test, based on the capture threshold test, select a pacing output configuration from among at least a low-voltage pacing output configuration of the low voltage therapy module and a high-voltage pacing output configuration of the high voltage therapy module; control a respective one of the low voltage therapy module and the high voltage therapy module to deliver extra-cardiovascular pacing pulses in the selected one of the low-voltage pacing output configuration or the high-voltage pacing output configuration via the extra-cardiovascular electrodes.