Magnetic field measurements from the Polar spacecraft reveal a field-aligned current system in the high-latitude, high-altitude magnetosphere that is the extension of the traditional region 1 and region 2 field-aligned current system observed at low altitudes. On average both the low- and high-altitude observations show that the region 1 and region 2 currents flow in opposite senses on the morning and afternoon sides. Recent studies reveal that negative (dusk to dawn) interplanetary magnetic field By extends the upward flowing region 1 current onto the morningside and positive By extends the downward flowing region 1 onto the afternoonside in the northern hemisphere. We use Polar magnetic field data to study both the local time and interplanetary-By orderings of the high-latitude, high-altitude, field-aligned currents. We find that the interplanetary-By component plays a very important role in controlling the flow sense of the field-aligned current at high altitudes. Except for small clock angles, the effect of the negative (positive) interplanetary By is an upward (downward) current both in the afternoon and morning sectors. ¿ 2000 American Geophysical Union