  We study the differences in chromospheric structure induced in K stars by
stellar activity, to expand our previous work for G stars, including the Sun as
a star. We selected six stars of spectral type K with 0.82$<B-V<$0.90,
including the widely studied Epsilon Eridani and a variety of magnetic activity
levels. We computed chromospheric models for the stars in the sample, in most
cases in two different moments of activity. The models were constructed to
obtain the best possible match with the Ca II K and the H$\beta$ observed
profiles. We also computed in detail the net radiative losses for each model to
constrain the heating mechanism that can maintain the structure in the
atmosphere. We find a strong correlation between these losses and \Sc, the
index generally used as a proxy for activity, as we found for G stars.
