A device for delivering electrical stimulation therapy to a patient, the device comprising: a plurality of implantable electrodes; two or more regulated current source or sink paths; one or more unregulated current source or sink paths; a stimulation controller configured to: selectively couple, via a regulated current source, a first electrode of the plurality of implantable electrodes to a regulated current source path of the regulated current source or sink paths to deliver a first amount of electrical stimulation current to the patient; selectively couple, via a regulated current sink, a second electrode of the plurality of electrodes to a regulated current sink path of the regulated current source or sink paths to deliver a second amount of the electrical stimulation current to the patient; responsive to the first amount of electrical stimulation current being greater than the second amount of electrical stimulation current, selectively couple, via a low reference voltage and a switch, a third electrode of the plurality of implantable electrodes to one of the unregulated current sink paths to deliver a third amount of the electrical stimulation current to the patient approximately equal to a sum of the first and second amounts of the electrical stimulation current; and responsive to the first amount of electrical stimulation current being less than the second amount of electrical stimulation current, selectively couple, via a high reference voltage and the switch, the third electrode to one of the unregulated current source paths to deliver the third amount of the electrical stimulation current to the patient approximately equal to the sum of the first and second amounts of the electrical stimulation current. a plurality of implantable electrodes; two or more regulated current source or sink paths; one or more unregulated current source or sink paths; a stimulation controller configured to: selectively couple, via a regulated current source, a first electrode of the plurality of implantable electrodes to a regulated current source path of the regulated current source or sink paths to deliver a first amount of electrical stimulation current to the patient; selectively couple, via a regulated current sink, a second electrode of the plurality of electrodes to a regulated current sink path of the regulated current source or sink paths to deliver a second amount of the electrical stimulation current to the patient; responsive to the first amount of electrical stimulation current being greater than the second amount of electrical stimulation current, selectively couple, via a low reference voltage and a switch, a third electrode of the plurality of implantable electrodes to one of the unregulated current sink paths to deliver a third amount of the electrical stimulation current to the patient approximately equal to a sum of the first and second amounts of the electrical stimulation current; and responsive to the first amount of electrical stimulation current being less than the second amount of electrical stimulation current, selectively couple, via a high reference voltage and the switch, the third electrode to one of the unregulated current source paths to deliver the third amount of the electrical stimulation current to the patient approximately equal to the sum of the first and second amounts of the electrical stimulation current. selectively couple, via a regulated current source, a first electrode of the plurality of implantable electrodes to a regulated current source path of the regulated current source or sink paths to deliver a first amount of electrical stimulation current to the patient; selectively couple, via a regulated current sink, a second electrode of the plurality of electrodes to a regulated current sink path of the regulated current source or sink paths to deliver a second amount of the electrical stimulation current to the patient; responsive to the first amount of electrical stimulation current being greater than the second amount of electrical stimulation current, selectively couple, via a low reference voltage and a switch, a third electrode of the plurality of implantable electrodes to one of the unregulated current sink paths to deliver a third amount of the electrical stimulation current to the patient approximately equal to a sum of the first and second amounts of the electrical stimulation current; and responsive to the first amount of electrical stimulation current being less than the second amount of electrical stimulation current, selectively couple, via a high reference voltage and the switch, the third electrode to one of the unregulated current source paths to deliver the third amount of the electrical stimulation current to the patient approximately equal to the sum of the first and second amounts of the electrical stimulation current.