  We have quantified the statistical uncertainties of the low-energy
coupling-constants (LECs) of an optimized nucleon-nucleon (NN) interaction from
chiral effective field theory ($\chi$EFT) at next-to-next-to-leading order
(NNLO). In addition, we have propagated the impact of the uncertainties of the
LECs to two-nucleon scattering phase shifts, effective range parameters, and
deuteron observables.
