  Production of K^{+} mesons in charged-current \nu_{\mu} interactions on
plastic scintillator (CH) is measured using MINERvA exposed to the low-energy
NuMI beam at Fermilab. Timing information is used to isolate a sample of 885
charged-current events containing a stopping K^{+} which decays at rest. The
differential cross section in K^{+} kinetic energy, d\sigma/dT_{K}, is observed
to be relatively flat between 0 and 500 MeV. Its shape is in good agreement
with the prediction by the \textsc{genie} neutrino event generator when
final-state interactions are included, however the data rate is lower than the
prediction by 15\%.
