  This report summarizes the present status of neutrino non-standard
interactions (NSI). After a brief overview, several aspects of NSIs are
discussed, including connection to neutrino mass models, model-building and
phenomenology of large NSI with both light and heavy mediators, NSI
phenomenology in both short- and long-baseline neutrino oscillation
experiments, neutrino cross-sections, complementarity of NSI with other low-
and high-energy experiments, fits with neutrino oscillation and scattering
data, DUNE sensitivity to NSI, effective field theory of NSI, as well as the
relevance of NSI to dark matter and cosmology. We also discuss the open
questions and interesting future directions that can be pursued by the
community at large. This report is based on talks and discussions during the
Neutrino Theory Network NSI workshop held at Washington University in St. Louis
from May 29-31, 2019 (https://indico.cern.ch/event/812851/)
