  We have observed 13 z >= 4.5 QSOs using the Multiband Imaging Photometer for
Spitzer, nine of which were also observed with the Infrared Array Camera. The
observations probe rest wavelengths ~ 0.6-4.3 micron, bracketing the local
minimum in QSO spectral energy distributions (SEDs) between strong optical
emission associated directly with accretion processes and thermal emission from
hot dust heated by the central engine. The new Spitzer photometry combined with
existing measurements at other wavelengths shows that the SEDs of high redshift
QSOs (z >= 4.5) do not differ significantly from typical QSOs of similar
luminosity at lower redshifts (z <~ 2). This behavior supports other
indications that all the emission components and physical structures that
characterize QSO activity can be established by z = 6.4. The similarity also
suggests that some QSOs at high redshift will be very difficult to identify
because they are viewed along dust-obscured sight lines.
