The physical conditions of the X-ray emitting corona in AGN, parameterised by the X-ray spectral index, Gamma, is dependent on the Eddington ratio. This has been shown from studies of broad-lined unobscured AGN and offers a way to estimate the Eddington ratio from X-ray spectra alone. We test this relationship for a sample of megamaser AGN that have typically lower-mass black holes, are highly inclined and heavily obscured, using NuSTAR data to account for the heavy obscuration. We find that the same relationship between Gamma and Eddington ratio exists for these sources, which has implications the isotropic emission of the corona, and hence AGN unification, and for estimating growth rates of heavily obscured AGN.