The evolution of differential energy spectra and distribution functions of H+, He+ and He++ across shock boundaries is examined to gain insight into the acceleration of solar wind and pickup ions by various types of shocks. Data from the SWICS and HISCALE instruments on Ulysses are combined in order to span the wide energy range from ∼0.6 keV/e to almost 5 MeV. We study two different types of shock crossings, the reverse shock of a Corotating Interaction Region, and the Jovian bow shock. Upstream ion velocity distributions are found to have hard suprathermal tails extending to high energies. Downstream ion distributions have higher particle densities in the tails, especially at energies corresponding to a few times the solar wind speed. At velocities greater than about ten times the solar wind speed the density increase from upstream to downstream is relatively small in the case of Jupiter’s bow shock. The presence of preexisting suprathermal tails provides particles with sufficiently high speeds to be re...