I will talk about Monte Carlo simulations devised to explore magnetized 
radiative transfer of polarized X rays in ionized atmospheres of neutron 
stars. We compute transport due to magnetic Thomson scattering sampling 
different magnetic colatitudes. Our results provide intensity and Stokes 
parameter angular distributions, indicating strong frequency-dependent polarization 
signatures from the persistent emission of magnetars. Polarization signatures 
for high opacity domains are presented, expediting the generation of emission 
signals from highly opaque stellar atmospheres. These computations are of 
significant interest for future X-ray polarimeters including IXPE.