  We present the spectro-polarimetric results obtained from simultaneous X-ray
observations with IXPE, NuSTAR and NICER of the dipping neutron star X-ray
binary 4U 1624-49. This source is the most polarized Atoll source so far
observed with IXPE, with a polarization degree of 2.7% $\pm$ 0.9% in the 2-8
keV band during the non-dip phase and marginal evidence of an increasing trend
with energy. The higher polarization degree compared to other Atolls can be
explained by the high inclination of the system ($i \approx 60${\deg}). The
spectra are well described by the combination of a soft thermal emission, a
Comptonized component, plus reflection of soft photons off the accretion disk.
During the dips, the hydrogen column density of the highly-ionized absorber
increases while the ionization state decreases. The Comptonized radiation seems
to be the dominant contribution to the polarized signal, with additional
reflected photons which significantly contribute even if their fraction in the
total flux is not high.
