  We propose a Stein characterization of the Kummer distribution on (0,
$\infty$). This result follows from our observation that the density of the
Kummer distribution satisfies a certain differential equation, leading to a
solution of the related Stein equation. A bound is derived for the solution,
under a condition on the parameters. The derivation of this bound is carried
out using the same framework as in Gaunt 2017 [A Stein characterisation of the
generalized hyper-bolic distribution. ESAIM: Probability and Statistics, 21,
303--316] in the case of the generalized inverse Gaussian distribution, which
we revisit by correcting a minor error in the latter paper.
