The NIST Database of Cross Sections for Inner-Shell Ionization by Electron or Positron Impact provides cross sections for ionization of the K shell and of the L and M subshells of neutral atoms of the elements, from hydrogen to einsteinium, by electrons or positrons, for projectile energies from the ionization threshold to 1 GeV. These cross sections were calculated from a combination of the relativistic distorted-wave and the plane-wave Born approximations.