A minimal extension of the standard model (SM) with a single new mass scale and providing a complete and consistent picture of particle physics and cosmology up to the Planck scale is presented. We add to the SM three right-handed SM-singlet neutrinos, a new vectorlike color triplet fermion, and a complex SM-singlet scalar sigma that stabilizes the Higgs potential and whose vacuum expectation value at similar to 10(11) GeV breaks lepton number and a Peccei-Quinn symmetry simultaneously. Primordial inflation is produced by a combination of s (nonminimally coupled to the scalar curvature) and the SM Higgs boson. Baryogenesis proceeds via thermal leptogenesis. At low energies, the model reduces to the SM, augmented by seesaw-generated neutrino masses, plus the axion, which solves the strong CP problem and accounts for the dark matter in the Universe. The model predicts a minimum value of the tensor-to-scalar ratio r similar or equal to 0.004, running of the scalar spectral index alpha similar or equal to -7 x 10(-4), the axion mass m(A) similar to 100 mu eV, and cosmic axion background radiation corresponding to an increase of the effective number of relativistic neutrinos of similar to 0.03. It can be probed decisively by the next generation of cosmic microwave background and axion dark matter experiments.