  We revisit the degeneracy between massive neutrinos and generalized theories
of gravity in the framework of effective field theory of cosmic acceleration.
In particular we consider f(R) theories and a class of non-minimally coupled
models parametrized via a coupling to gravity which is linear in the scale
factor. In the former case, we find a slightly lower degeneracy with respect to
what found so far in the literature, due to the fact that we implement exact
designer f(R) models and evolve the full linear dynamics of perturbations. As a
consequence, our bounds are slightly tighter on the f(R) parameter but looser
on the summed neutrino mass. We also set a new upper bound on the Compton
wavelength parameter ${\rm Log}_{10}B_0<-4.1$ at 95% C.L. with fixed summed
neutrino mass ($\sum m_{\nu}=0.06$ eV) in f(R) gravity with the combined data
sets from cosmic microwave background temperature and lensing power spectra of
Planck collaboration as well as galaxy power spectrum from WiggleZ dark energy
survey. We do not observe a sizable degeneracy between massive neutrinos and
modified gravity in the linear parametrization of non-minimally gravitational
coupling model. The analysis is performed with an updated version of the
EFTCAMB/EFTCosmoMC package, which is now publicly available and extends the
first version of the code with the consistent inclusion of massive neutrinos,
tensor modes, several alternative background histories and designer
quintessence models.
