A modification of the action of the general relativity produces a different pattern for the growth of the cosmic structures below a certain length-scale leaving an imprint on the cosmic microwave background (CMB) anisotropies. We re-examine the upper
limits on the length-scale parameter B0 of f (R) models using the recent data from the Planck satellite experiment. We also investigate the combined constraints obtained when including the Hubble Space Telescope H0 measurement and the baryon acoustic oscillations measurements from the SDSS, WiggleZ and BOSS surveys.
