  We combine results from CDF and D0 on direct searches for a standard model
(SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at
sqrt(s)=1.96 TeV. Compared to the previous Tevatron Higgs search combination
more data have been added and some previously used channels have been
reanalyzed to gain sensitivity. We use the latest parton distribution functions
and gg->H theoretical cross sections when comparing our limits to the SM
predictions. With 2.0-4.8 fb-1 of data analyzed at CDF, and 2.1-5.4 fb-1 at D0,
the 95% C.L. upper limits on Higgs boson production are a factor of 2.70 (0.94)
times the SM cross section for a Higgs boson mass of m_H=115 (165) GeV/c^2. The
corresponding median upper limits expected in the absence of Higgs boson
production are 1.78 (0.89). The mass range excluded at 95% C.L. for a SM Higgs
is 163<m_H<166 GeV/c^2, with an expected exclusion of 159<m_H<168 GeV/c^2.
