Skilled immigrants in the US boost innovation by patenting at double the rate of native individuals, mainly due to their backgrounds in science and engineering. For every one percentage point increase in the share of immigrant college graduates, patents per person increase by 6%. Immigrants also have positive spill-over effects on native inventors, leading to a 9-18% increase in patents per person for every one percentage point rise in immigrant college graduates. This shows that skilled immigrants contribute significantly to innovation in the US.