Abstract: Multiple reservoir implantable valve accumulator pump for the delivery of medication, and method of infusate delivery. The apparatus includes at least first and second infusate reservoirs in a common pressure chamber, each in fluid communication with a metering assembly. The metering assembly includes an accumulator that is preferably a fixed volume accumulator having an inlet and an outlet. A first valve is in fluid communication with the first infusate reservoir and an inlet of the accumulator, and a second valve is in fluid communication with the second infusate reservoir and an inlet of the accumulator. An outlet valve is in fluid communication with the outlet of the accumulator. The accumulator can be filled with infusate from the first and second infusate reservoirs sequentially, can be filled from the first infusate reservoir multiple times consecutively, the second infusate reservoir multiple times consecutively, or any combination or permutation thereof.