Medical device with multiple channel independent rate control

Techniques are described in this disclosure for delivering electrical stimulation therapy to a patient over multiple channels, with independent rate control for each channel, using a single stimulation generator. In one example, the disclosure describes a method for delivering electrical stimulation therapy to a patient that includes delivering first electrical stimulation pulses at a first programmed rate on a first channel using a stimulation generator, and delivering second electrical stimulation pulses at a second programmed rate on a second channel using the stimulation generator, the second programmed rate being different than the first programmed rate, and the second programmed rate being independent of the first programmed rate.