  We present the latest combination of searches for a standard model (SM) Higgs
boson in ppbar collisions at \sqrts= 1.96 TeV recorded by the CDF~II detector
at the Fermilab Tevatron. Using data corresponding to 2.3-5.9 fb-1 of
integrated luminosity, we perform searches in a number of different production
and decay modes and then combine them to improve sensitivity. No excess in data
above that expected from backgrounds is observed; therefore, we set upper
limits on the production cross section times branching fraction as a function
of the SM Higgs boson mass (mH). The combined observed (expected) limit is 1.9
(1.8) times the SM prediction at mH = 115 Gev/c^2 and 1.0 (1.1) times the SM
prediction at mH = 165 GeV/c^2.
